Fossil Friday
Teleoceras Medicornutum from the Middle Miocene (Barstovian) of Southwest Mississippi
Fossils are incredibly important tools for geologists. They are essential for unlocking the details of deposits and in determining both environment and time. This is especially true in parts of the geologic section that seem largely barren of fossils. In those cases, every detail can offer scientists valuable world clues.
A good case study for this is the geology of south Mississippi. Here the Grand Gulf Group outcrops from the southern edge of capital city in Jackson to the Gulf of Mexico. Sedimentary deposits of Grand Gulf Group span the time from the late Oligocene to Pliocene in age and reach a maximum thickness of three to 5,000 feet of section.
Determining and constraining the age and stratigraphic boundaries of the individual formations that make up these deposits has been a major challenge for geologists for a very long time. This is because this part of the geologic section is almost completely terrestrial and contains very few fossils.
Plant fossil sites are the most common occurrence in south Mississippi. They are important environmental indicators, but they lack the necessary information that fossils of marine organisms can tell us about their age. The occasional find of the rare occurrences of terrestrial vertebrates in south Mississippi has recently been able to give us this great insight.
A happen-chance finding of a fossil bone at a hunting camp near Meadville, Mississippi in Franklin completely changed our understanding of the geology of the area. It was brought to the attention of the camp by one of the members and was dismissed as a cow bone. Not satisfied with that answer, he brought it to the attention of the Mississippi Museum of Natural Science in Jackson, who immediately contacted MDEQ’s Mississippi Office of Geology for a joint investigation of the find.
The find turned out to be the fossil leg bone of a type of ancient rhinoceros. Rhinoceros are part of a group of mammals called perissodactyls that evolved right here in North America about 55 million years before spreading to other parts of the globe. Rhinoceros became extinct in North America about five million years ago. So how does this find help us to better understand the geology of south Mississippi?
Being able to identify the fossil rhinoceros down to a specific species answers many questions. This fossil find was carefully studied and shared with other researchers to help narrow it down. The fossil bone was specifically from a stout legged rhinoceros named Teleoceras that lived from the Miocene to early Pliocene. These animals were semi-aquatic and lived along coastal swamps and freshwater river deltas similar to modern hippopotamuses.
Because this fossil bone was so well-preserved it could be narrowed down to a specific species, Teleoceras medicornutum. This animal lived during a narrower time frame in the middle part of the Miocene epoch called the Barstovian, which is the North American Land Mammal Age that lasted from 16.3 to 13.6 million years ago. From this one rare fossil we were able to reconstruct the geologic age, depositional environment, and reconstruct an ancient habitat for this part of the geologic section where before this discovery we knew so little about.
Pelletal Jaspers From Mississippi Gravel
Pelletal Jaspers are a chert-replacement of iron-rich pelletal carbonate mudstones derived from Paleozoic bedrock that once formed in ancient tropical, near-shore marine environments. Today’s example comes from the Pre-loess Terrace gravel photographed by MDEQ, Office of Geology staff in the field this week in Yazoo County, Mississippi. Most geologists that study petrology and how sediment forms think that pellets are an accumulation of many tiny fossils, called coprolites. They are thought to be the fecal products of invertebrate organisms because of their consistent size, shape, and very high iron content. Pelletal jasper forms from chert replacement of Pelletal limestones and were carried here from Paleozoic bedrock sources up in the mid-continent by ancient rivers. Two types of pelletal jasper, red and green, are both available in the Pre-loess Terrace gravels along the bluffline and are also a constituent of the Mississippi River gravels. The differences in color of pelletal jaspers are derive from the state of their iron impurities. Red, the most found variety, like the example in today’s Fossil Friday. It gets its color from iron in an oxidized state. The less common color, green, is also due to iron, but iron in a reduced state. These high-quality jaspers were culturally utilized for a few implements and ornaments in Mississippi’s rich prehistoric archaeological record. Most notably, in the ancient Native American lapidary industry that began in the Middle Archaic cultural period and saw its height in the lower Mississippi Valley during the Late Archaic cultural period. Due to the texture and color variety of pelletal jaspers, they often can be mis-identified in describing artifacts from our ancient archaeological record. The gravel clast-size pelletal jasper can range widely, from small pebbles to large cobble size specimens. Other types of local jaspers found naturally here (and similarly utilized from our gravels) are banded-iron formation jaspers (originating from bedrock much further up the watershed of the Mississippi River) and chert jaspers (which are basically just red chert, either natural or from heat-treatment).
Excavation of a Cretaceous Mosasaur Fossil by MDEQ’s Office of Geology for the Mississippi Museum of Natural Science
The discovery of an important mosasaur fossil was made in July of last year by the Mississippi Museum of Natural Science’s paleontologist and their Special Events coordinator as they were passing through an area that the Museum had worked several years ago for studies on Pleistocene fossils. They had stopped again to visit this old fossil research haunt to look for more Pleistocene age fossils eroding from the alluvium outcrops along a small drainage through a vast expanse of agricultural fields. The floor of these small drainages in this part of northeast Mississippi often exposes fresh Cretaceous age bedrock underneath that once was part of a shallow tropical sea.
This vast prairie region of northeast Mississippi is important for agriculture but is also unique and very important scientifically in other respects. They are windows into two distinctly different ancient worlds that can only be viewed here.
Fossils of both extinct ice age and dinosaur age animals can be found near one other another. But they are separated vastly by both time and environment. Fossils of ice age animals that used to live on this rich prairie land are tens of thousands of years old. While fossils from marine environments from the days of the dinosaurs that form the limestone bedrock that underlies this area are upwards of 80 plus million years in age. This dinosaur age bedrock weathered over many thousands of years to form the rich prairie soils that sustain the farmlands of northeast Mississippi.
The museum’s scientists must have had their attention focused on looking high up in the outcrops of the ice age stream alluvium along the walls of the drainage because they had only noticed the dinosaur age fossil bones, a giant jaw full of teeth partially exposed in the floor of the drainage, on their way back out. The bones imbedded in the rock are not much different in color or texture than the ancient limestone they are contained in.
The Mississippi Museum of Natural Science paleontologist immediately recognized the type of fossil it was by the shape of the teeth and jaw as a mosasaur fossil, possibly of the genus Clidastes. Mosasaurs were a diverse group of marine lizards that inhabited various ocean environments of the Late Cretaceous period. These animals lived at the same time as Tyrannosaurs rex, Velociraptor, and Triceratops. Clidastes were relatively small to medium sized mosasaurs (reaching only about 20 to 30 feet in length). The skull of this specimen was approximately 4 feet in length.
These types of mosasaurs were fast and very agile swimmers. They were highly adapted to hunting in the late Cretaceous seas. They sported jaws full of up to 60 dagger-like sharp pointy teeth that were curved inward, with additional rows of teeth at the roof of the back of their mouths to help secure larger prey. Mosasaur’s teeth were frequently lost and replaced while hunting fish, swimming shellfish called ammonites, other marine reptiles, and likely each other.
Mosasaurs were sea dragons both large and small and were truly the apex predators dominating the various environments of the seas of this time. Some mosasaurs, such as Tylosaurus reached over 50 feet in length. While the dinosaurs ruled the land, these Mesozoic era oceans were likely the most dangerous of any time in the entire history of our planet.
The museum immediately contacted MDEQ’s Office of Geology research staff to coordinate a paleontological recovery excavation. The team returned the next day to carefully photograph and excavate the near perfectly preserved lower jaws that were exposed in fossil-rich marine limestone of the ravine. The team of scientists noticed while we were there salvaging the toothy jaws, that other elements of the skeleton were also present, fossil vertebrae and ribs scattered about nearby. They carefully removed the randomly scattered pieces of bone that were associated with the jaws because they were also at risk of further eroding out of the hard limestone ground and lost forever.
The scientists realized that that there was likely much more to the fossil specimen buried just below the surface. Excavating any further would certainly have put at risk damaging any remaining bones of the underlying mosasaur fossil that they could not readily see embedded in the limestone just below the surface. They all agreed that the best thing would be to continue to monitor the site over time as erosion of the bedrock naturally took place and quite possibly naturally and more delicately exposed many more bones of the mosasaur fossil.
Based on our earlier studies of the geology of the area by the State Survey program and knowledge of the other invertebrate fossils contained in the limestone, we know that this mosasaur was alive in a part of the late Cretaceous known as the Campanian age. After death, this mosasaur came to rest on top of the shells of an oyster bed where it was quickly buried by muddy lime deposits off the bottom of a warm tropical shallow sea. Over the next tens of millions of years, the seas dried up and left this area and retreated to what is now the Gulf of Mexico. The limestone lithified and encased the skeleton of this mosasaur in what geologists call the Mooreville Formation. This geologic formation has been precisely dated to about 82 million years old.
Seashells fossil are commonly found by our geologists in these marine outcrops and are also encountered in wells drilled by our scientists through these rock layers. It is because of detailed studies of these fossils that our scientists studying the paleontology of these rock units know where they are in geologic time. These geologic formations are divided by our mapping geologists by studying the ancient ecosystems of fossils that each formation contains. They also conduct detailed studies of the types of environments the deposits were formed in, which are the sediments that the fossils are found in.
Isolated bones and teeth of mosasaurs, other ferocious marine lizards, and various sharks and fish that ruled this terrifying sea in the Late Cretaceous period are relatively common fossil finds along these limestone outcrops in the prairie region of northeast Mississippi. Even isolated finds of dinosaur bones have been found in this area from carcasses that once got swept out to sea by ancient storms and floods and then scavenged by sharks. But associated bones from a single individual animal are very rare and partial or even more complete skeletons are extremely rare from any period of the fossil record and therefore are exciting finds for scientists. Mosasaurs just like the dinosaurs, went extinct at the end of the Cretaceous period.
In late July of this year. A return trip to the fossil site was made by our MDEQ survey geologists. A brief stop was made to the fossil site. This was done between giving an educational program to kids on rocks and fossils at a 4-H Summer Earth Camp in Starkville and a professional visit to the Union County Heritage Museum in New Albany, Mississippi for a new exhibit of our newly adopted Official State Gemstone on display. On this brief return visit to the fossil site, we noticed that now much of the skull of Mosasaur was now visible and plans needed to be quickly made to properly excavate it.
A return trip to further excavate the mosasaur fossil remains was made the first week of August. The scientists began the laborious process of excavating the skull from the bedrock in a single block of limestone instead of trying to remove the delicate bones individually in the field. This would be more properly done delicately in a controlled environment than in the field. A six-inch-high earthen dam was constructed around the large 5-foot by 3-foot block to be carved from the bedrock. The dam was constructed from loose sediment in the ravine to try and keep the trickle of water out of the excavation that was running through the narrow ravine. Water was bailed by from the excavation by hand to keep the block as dry as possible. This was just marginally successful as water kept finding its way back in through the loose soil dam as the team worked in the summer heat.
They had made it through most of the first day and successfully prepared part of the block just before a violent thunderstorm erupted and trapped, trapping the team in the narrow ravine to ride it out. Straight line winds from the squall line were more than 70 miles an hour battered the team for what seemed like 10 minutes and scattered all their field equipment about.
They had no choice but to abandon the excavation when the rain slacked up, because more heavy storms were visible on the radar and were heading their way. The next morning, they spent gathering up our equipment and securing the site to try again to regroup sometime later. They hated to leave it but it was starting to thunder again as they left the site again and the weather pattern was forecasted to be more unstable in the coming days.
Every major paleontological excavation poses a unique set of conditions and challenges for scientists in the field. It is essential for the success of the projects to be able to adapt to those challenges. Over the next two weeks that followed more detailed plans were made for the return to the dig site to finish the removal of the massive limestone block containing the mosasaur skull fossil. Geology staff gathered some additional tools, rigged up a small submersible pump and battery to keep the water out the excavation, bentonite clay to help seal the soil dam around the excavation, a long steel cable to use as a makeshift two-man rock saw to help separate the massive block from the bedrock, and designed a sled system from an old metal road sign and a wooden pallet to move the massive block once extracted from the bedrock.
Their return trip was on August 22 and the forecast was clear with no possibility of rain but was also projected to be one of the hottest weeks ever on record in Mississippi.
The team returned to the site and they found theirs earthen dam had washed across much of the excavation block which helped protect the exposed fossil bones from the elements. But the earthen dam had to be re-built and the mud and sand around block re-excavated to the state of the previous progress. The 50lb bag of bentonite clay they brought sealed the dam just as planned and the submersible pump and car battery worked exquisitely to drain the excavation.
Quick work was then made the first day with rock hammers, pickaxes, sledgehammers, and a rotating bucket brigade to finishing excavating a trench in the limestone around the large block and properly pedestal it. The work went on tirelessly throughout the day in temperatures reaching above 103 degrees. That evening, before the removal of the block could begin the following morning, a burlap and plaster jacket was placed over the pedestaled block to protect it for later transport and was left to dry overnight.
The next morning efforts began to undercut the pedestaled and plaster-jacked block containing the delicate bones of the mosasaur skull. This was done by going around the bottom edge of the pedestal using the steel cable like a two man saw. After a few grueling hours sawing around the rock, the pedestal was successfully undercut by about 6 inches all the way around the pedestal block.
Stakes were then driven with a sledgehammer into the rock all around the base of the pedestal and into undercut part of the block to break it free from the bedrock beneath in one massive piece. Once it was broken free from the bedrock, the 1,000+ pound block containing the intact fossil skull was lifted by hand onto the makeshift sled.
The sled was strapped to a wooden pallet for stability. The 1,000+lbs sled and block were dragged together by all 6 scientists for approximately 75 yards downstream to an opening along the edge of the ravine. By this time of the day temperatures had surpassed 105 degrees. The enormous, jacketed block was now successfully moved with minimal damage into position where it could be winched up with the sled 20 feet along a nearly vertical bluff with the aid of a powerful truck winch mounted on the front a heavy-duty pickup truck.
Once out of the ravine the important Mosasaur fossil had to dead lifted by hand into the back of the truck by all 6 scientists, where it rode for about 3 hours back to the Mississippi Museum of Natural Science in Jackson. Once it arrived, it was greeted with much excitement by the museum’s staff. It was forklifted from the truck and placed indoors. The top of the plaster jacket was removed to see what condition the block with the mosasaur skull fossil inside was in after the long haul. Elation was felt all around that it appeared to be in nearly perfect condition, still embedded in the solid rock, just as it was when it was first discovered.
The removal of a block of rock this size containing an intact vertebrate specimen is a monumental task in paleontology. Though it took time, it was widely successful because of the collective expertise of the scientists involved. It now can be properly excavated and studied in a temperature and climate controlled scientific environment using laboratory techniques and tools not practical for field studies.
Enormous amounts of data and measurements will be collected on the mosasaur fossil. It will be used to compare with others that have been described from around the world. These findings and comparisons will be published as research in the scientific community. Being able to carefully study the marine sediments and other fossils around this mosasaur fossil in a laboratory setting can additionally help to tell a deeper story. These important details include clues about the sea the animal lived in, what type of animals could have been feeding on its carcass, and details surrounding the circumstances of the environment that it was buried in and ultimately was preserved in.
The value of the preservation of this extremely rare specimen to the international scientific community and for Mississippi’s natural history is immeasurable. It will only be realized through future careful multidisciplinary studies on this amazingly well-preserved fossil.
The rest of the fossil is likely buried beneath several feet of limestone and may never be completely recovered, but the site will be continually monitored over time as more bones from this mosasaur specimen might be further revealed by natural erosion.
A Really Neat Fossil Find From Samantha Barnes Along The Pearl River.
Our State Survey geologist at MDEQ’s Office of Geology are fielding questions daily from the curious public about their rock and fossil finds from around the state. This intellectual curiosity about the natural world around us fuels important scientific discoveries and fosters conservation minded stewardship of our environment.
Earlier this week, the young fossil hunter Samantha Barnes brought to our scientist’s attention an interesting fossil that she had found while rock hunting along the Pearl River in Hinds County, Mississippi. Samantha quickly noticed the patterns and shapes in the rock she had picked up. She was certain she had discovered some kind of a fossil, maybe even more than one fossil embedded in the rock, and indeed she did!
Samantha was curious if the fossils could date back to the days of the dinosaurs. What she had discovered along the Pearl River that day was a collection of marine invertebrate fossils preserved in the rock from the Paleozoic era. The fossil were once the skeletons of ancient sea creatures that are way older than the days of the dinosaurs and came to rest on a tropical sea floor hundreds of millions of years ago.
Some of the fossils in the rock Samantha described to our scientists as a “scaly skin-like pattern in the rock”. These turned out to be the well-preserved impressions of an extinct colony of animals called fenestrate bryozoan. These lace-like animals would have been somewhat similar in appearance to a modern fan coral.
The other fossils she noticed in the rock were small cylindrical-shaped fossils that were identified as crinoid stem ossicles. Crinoids are called “sea lilies” but are actually not plants, but unusual animals related to starfish, brittle stars, and sea urchins. There skeletons are made up of numerous mineralized elements called ossicles that tend to disarticulate after the animal dies. Crinoids are living fossils that have persisted in the worlds oceans for hundreds of millions of years. They still inhabit unique environments in the oceans today.
Spectacular gravel fossil finds like Samantha’s are often people’s first introduction to the science of Paleontology in Mississippi. To help facilitate this widespread interest for people of all ages, MDEQ has published an educational resource for fossil hunters like Samantha called “Rocks and Fossils Found in Mississippi Gravel”. It is available for free download: Rocks And Fossils Found In Mississippi’s Gravel Deposits – MDEQ
Stream Alluvium – Mississippi’s Treasure Chest of Paleontological History.
Stream alluvium is an important geologic unit that can be mapped all over the state. The tapestry of dendritic stream systems coalesces across the landscape to form larger rivers as they drain their way towards the Gulf of Mexico. The alluvium of a stream is the assortment of sand, silts, muds, gravels, and clay material deposited by the movement of water in the stream as carries the sediment along its valley that was eroded from the adjacent uplands within its water shed.
This stream sediment, collectively called alluvium, is an important environmental resource for a multitude of reasons: streams and their bottomland alluvial plains provide a rich and essential habitat for wildlife and botanical ecosystems. The fertile floodplain soils are the staple for agriculture in Mississippi. Groundwater found in alluvium comprises the largest and most environmentally sensitive shallow aquifer system in the state.
Did you know it is also one the most important paleontological resources we have in Mississippi? Streams carry with them and quickly bury the remains of animals, plants, and even human artifacts. These fossils are often deposited during major flooding events where they become locked away from time and the elements perfectly preserved in the wet sediments. These time capsules are later revealed again by the same stream process that once buried them as the constantly migrates slowly back and forth across its flood plain, eroding its banks.
Stream alluvium in Mississippi can be quite ancient and can date back as far the Pleistocene. Most of the ice age vertebrate fossils found in Mississippi, along with most of the Native American artifacts from various cultural time periods are found along streams. These fossils and artifacts found eroding from the alluvium date back many thousands of years or even many centuries. The floodplains of streams also host the largest concentration of archaeological sites than any other geomorphological features in the state. Though they are more prone to the effects of natural disasters, the resources provided by life on the floodplains are rich and unmatched from any upland environment.
Stream alluvium can also incorporate and concentrate large amounts of fossils from much older deposits. These fossils dating back millions of years are eroded from the underlying bedrock by the force of water running through the stream’s channel.
In the photo, you’ll see an outcrop of Pleistocene age stream alluvium from an outcrop being studied in the bluffs of Yazoo County by MDEQ’s Office of Geology research staff in the Surface Geology Division of the State Survey. Also, photographed is an ancient fossil log from the last ice age that eroded from this outcrop. It is nearly perfectly preserved, even after many thousands of years. Mastodon bones and other extinct Pleistocene animal remains were found at this outcrop on previous visits to study this stream alluvium fossil site.
These botanical remains are an important window into the ancient past. We are actively collecting these plant fossils and working with other scientists to study what the habitat along these streams was like during the last ice age. These Pleistocene plant fossils reveal a bottomland hardwood environment that would be more familiar in much more northern climates than that of the Gulf Coastal Plain of today.
The Drew McGahey Clovis
Humans entered the paleontological record in Mississippi at some point during the last ice age. The Native Americans that first arrived, in what we know as Mississippi, encountered an environment that would seem quite strange to us today. The plants of the forests, the bottomlands, and even prairies would be more familiar in modern northern climates than to those of Mississippi today. The landscape hosted an even stranger variety of animals that are now long extinct.
Geology is the basis for the environment and is an integral part of archaeology. Geologic mapping is essential to understanding the age of landscapes, their paleoenvironment, and the distribution of natural resources available to their inhabitants. It is also important for characterizing depositional environments and the geochemistries that are conducive to the preservation of these important archaeological resources.
The stone tools, called lithics in archaeology, that these Pleistocene inhabitants left behind are often the only evidence that we have of their presence here in Mississippi. Because of this, the analysis of lithic is typically the only window we have to study and learn about these first peoples’ relationship with that ancient environment.
The ice-age first people’s cultures are known by their tool styles or traditions and are collectively referred to by the scientists who study them as Paleoindian. They were thought to be highly specialized nomadic hunters, of the now extinct megafauna of late Pleistocene, as evidenced by their exquisitely made stone tools and the scarce number of longer-term occupation sites that they left behind.
The discoveries of most of the known early Paleoindian artifacts in North America are quite happen-chance. They are often stumbled upon by landowners, collectors, and rock hobbyists; and very rarely by professional researchers in the field. This makes the general public, those who have found and collected these artifacts, typically the primary resource for information we, as scientists, have to study this earliest human time period here in Mississippi’s cultural prehistory.
Earlier this year, a Clovis point was found in a creek by a young man and brought to the attention of our Surface Geology staff. Clovis are the earliest recognized human artifacts found in Mississippi. This important discovery was made by Drew McGahey in northwest Copiah County.
This was a special find for several reasons. Drew is the grandson of the late State Archaeologist, Sam McGahey, whose work while at MDAH helped set the foundation for Paleoindian research in Mississippi. MDEQ, staff geologists worked with Sam over many years conducting and publishing research on the state’s geoarcheology. Drew’s find was also exciting as it is relevant to our recently published work and detailed geologic mapping that our Geology research staff have conducted in that area.
Drew’s Clovis artifact can reveal some very important clues about the ice-age people who lived in the area and their utilization of the resources in their environment. The Drew McGahey Clovis was found is a gravel-choked creek bed rich with excellent quality stone resources derived from the Pre-loess Terraces beneath loess in the uplands of the area. These gravel creek beds would have been mined for their exquisite quality chert, large gravel cobbles, and other important types of high-quality stone resources. It not uncommon to find artifacts that are evidence of the procurement of these resources such as tested cobbles and hammerstones amongst the gravel of in the creeks of the western loess bluffs.
The flood plains of these creeks would have once been home to an abundance ice-age wild game such mastodon, bear, horses, sloth, and tapir. But the ice-age hunter would have to across the rugged terrain of loess hills to venture out of these narrow creek bottoms to explore neighboring drainages. Fossil bones and teeth of these ice age animals are also commonly found along these drainages.
The Drew McGahey Clovis demonstrates a clear familiarity with working the locally-available gravel resources of Pre-loess Terrace Deposits by adopting the Clovis tradition and knapping methodology to the inherent properties of gravel resource.
Because of the geology and the geochemistry of the loess soils in the area the Drew McGahey Clovis was found, the potential for the preservation of early sites with things other than stone artifacts is possible. The find of this point outside of that type of context is still very important as it shows that people were indeed living nearby and utilizing the resources of the area. This also leaves open the potential that we may yet, one day, find an intact archeological site dating to the ice age in this type of environment with excellent preservation.
As other early artifacts, like the Drew McGahey Clovis, come to light and the potential for discoveries of intact archaeological sites, becomes more evident; a more complete, and likely more complex picture will emerge about the life ways of Mississippi’s first inhabitants during the last ice age.
Our State Survey geologists at MDEQ are actively involved in working collaboratively with geological surveys of neighboring states, the National Park Service, and other agencies. This essential Survey research is encouraged through the state and by research grants funded by USGS and the NPS.
This week we feature a steinkern (internal cast) of the shell of the terminal Cretaceous Baculitid ammonite fossils from the Owl Creek Formation. This fossil was found in Union County last month near the K/Pg extinction boundary while conducting field research with the paleontology program at the Mississippi Museum of Natural Science.
Ammonites are an extinct group of shelled cephalopods, a diverse groups of predatory mollusks that are relatives of modern octopus and squid. For over 300 million years of our earth’s history the worlds oceans were teeming with a wide diversity of ammonites.
These cephalopod shell fossils are very important to mapping geologists and paleontologists in the field. They are excellent time boundary indicators because of their rapid rate of evolution and world-wide distribution in the marine sedimentary record.
Ammonites and their cousins, the nautiloids, lived together until the extinction event that killed off the dinosaurs, along with 75% of all life on earth, at the end of the Cretaceous period. This was when most all of Mississippi, and much of the coastal plain of our state and our neighboring states was covered in a shallow tropical sea.
Nautiloids inexplicably survived the extinction event at the end of the Cretaceous while ammonites did not and in doing so they flourished in the recovering ecosystems of the oceans. Today, the Nautilus is the sole living shelled cephalopod swimming the world’s oceans.
Different depositional environments and their fossil assemblages, called “facies” by geologists, are recorded across the coastal plain of the Northern Gulf of Mexico.
Because of this, open marine to shallow marine deposits of the late Cretaceous can be best studied in the central part of Northeast Mississippi, while the shallower marine to terrestrial facies from the same time period can be best studied further north approaching the Tennessee line.
Mississippi is known by many scientists to have some of the best preserved fossils in the world, going all the way back to the last days of the dinosaurs. Our featured fossil ammonite still retains some of its original mother-of-pearl from late Cretaceous period 66 Million years ago. This is because many of our fossils are not actually fossilized (mineralized) which preserves exquisite and rare details about the fossil not seen anywhere else. This means that they are actually still composed (all or in part) of their original organic materials, even though they can be many millions of years old.
Fossil like these and other things like shells, bone, teeth, and even wood that have not been altered by mineralization are extremely important to our scientists. They hold important detailed information about things like the life, diet, and even the environment of a long extinct species of plant or animal. This kind of biological data is completely lost in deposits that contain mineral-replaced fossils.
Before sea levels dropped and the Petrified Forest came into existence, much of Mississippi was covered in a deep ocean. In fact, during this time called the late Eocene (some 40 million years ago), the entire world saw much higher sea levels than that of today. Some of the same marine fossils found in the Yazoo Clay of Mississippi can also be found in the limestones that make up the pyramids of ancient Egypt.
During the late Eocene, the world had been in a greenhouse environment continuously since the days of the dinosaurs. Fossils of true giants can be found preserved in the Yazoo Formation such as the skeletons of toothed whales, the Basilosaurs, which where the largest creatures on earth at the time. They swam the Jackson Sea which is now Madison County with other large marine vertebrate such as a giant swordfish called Xiphiorhynchus.
But arguably, nothing at this time was more formidable in the oceans than the megatoothed shark, Carcharocles/Otodus auriculatus. This monster of a shark was one of the largest of its kind that ever existed. It’s teeth alone, though rather rare fossil finds in Mississippi, are a testament to just how awesome these creatures truly were. Their serrated teeth can reach up to almost five inches in length and over four inches wide. It is estimated that these shark could reach lengths of 30 feet or more and weighed up to eight tons.
This features an amazing find of a perfectly-preserved and truly giant example of a Madison County megatoothed shark from Charcharocles/Otodus auriculatus. It was discovered and collect by Russ Chandler from an outcrop the Yazoo Formation near Flora. Russ quickly brought his find to the attention of our MDEQ, State Geological Survey geologists for identification and documentation. Documenting this amazing find will be a great contribution in helping our scientists better understand our state’s rich natural history.
At the close of the Eocene, sea levels dropped and temperatures cooled causing the Basilosaurs to die out. This left these megatoothed sharks with no real competition from other sizable predators in the worlds oceans. Over geologic time their ancestors grew to even grander sizes, culminating in largest shark to ever live, Carcharocles/Otodus megalodon. C./O. megalodon thrived during the early Miocene and Pliocene epochs before further environmental changes in the ocean temperatures wiped them out some 3.6 million years ago.
This fossil called Rhyncholampas goulgi was collected last month by MDEQ’s Office of Geology staff while leading a paleontological field trip in Smith County. The educational exercise was conducted in coordination with the Mississippi Museum of Natural Science for their summer Naturalist Camp. During this portion of the camp, students were introduced to the environmental science of geology and Mississippi’s rich natural history through paleontology and stratigraphy.
R. gouldi is small cassiuloid echinoid (about the size of a walnut) that once inhabited the warm shallow waters of the Gulf of Mexico during the earlier Oligocene (Rupelian), some 30 million years ago. This specimen was found in the Mint Springs member of the Vicksburg Group, which was deposited in a near shore environment. R. gouldi was a bottom feeder and was covered in a fine layer of short, bristle-like spines that it used for both protection and locomotion along the sea floor.
The limestones deposited in this area during that time are known as the Vicksburg Group, because they were first described by scientists from prominent outcrops along the Mississippi River in the vicinity of Vicksburg. Also, the deposits and the ocean here at that time are referred to as forming in the Vicksburg Sea. The fossiliferous limestones of the Vicksburg group form a narrow set of aggressive hills just south of the Jackson Prairie from Vicksburg through Byram, Brandon, and southeast through Waynesboro.
This post features the release of the Gulf Islands National Seashore Paleontological Resource Inventory (Public Version) Natural Resource Report NPS/GUIS/NRR-2023/2525 by the Department of the Interior.
This is the fourth recent National Park Service publication acknowledging the help of MDEQ’s Office of Geology geologists. These recent reports include a Geology Report, on the Paleontological Resource Inventory of Vicksburg National Military Park (Public Version) was also released last month. with the acknowledgment that: “This report would not have been possible without the invaluable assistance of the Mississippi Department of Environmental Quality (MDEQ) Geologists”
Recently, our State Survey geologists at MDEQ have been working with and publishing paleontology research with the Geologic Survey of Alabama geologists, and paleontologists with the McWane Science Center and University of Louisiana, Monroe on the occurrence of Pliocene Graham Ferry fossil shark teeth and otoliths showing up on the beaches of Dolphin Island.
The Geologic Map of Jackson County (with portions of Harrison, George, and Stone counties), published in MDEQ Office of Geology as Open File Report OF-285 was used by the NPS authors and was instrumental in revising the geology from an earlier 2016 report by the NPS of the Gulf Islands National Seashore. Instead of recognizing the “Citronelle Formation” onshore and under the islands of the Gulf Islands National Seashore, individual coastal terraces are now recognized overlying the Pliocene Graham Ferry Formation, which is also an aquifer for coastal counties in Mississippi and Alabama. This foundational geologic work, Open File Report OF-285 was made in cooperation with the Office of Land and Water Resources with authors Lindsey Stewart and James Starnes.
This geologic mapping is not only being issued as the context for understanding the paleontology and geologic history of the Gulf Islands National Seashore National Park, it is being used to update out state’s stratigraphic nomenclature and as the basis for updating contiguous mapping by the geological surveys of Louisiana, Alabama, and Florida.
NPS’s Gulf Islands report: Click here.
Geological Map of Jackson County
For more information on the geology of Jackson County: OF-285 Surface Geology of Jackson County, Mississippi – MDEQ
Our State Survey geologists at MDEQ are actively involved in working collaboratively with geological surveys of neighboring states. This research is encouraged through research grants funded by the USGS.
This week we feature a steinkern (internal cast) of the shell of the nautiloid, Hercoglossa ulrichi from the Paleocene of Alabama, measuring approximately 14 cm. In diameter.
Nautiloids are shelled cephalopods, a diverse groups of predatory mollusks that are relatives of modern octopus and squid. For over 300 million years of our earth’s history the worlds oceans were teeming with nautiloids along with their cousins the ammonites.
Cephalopod shell fossils are very important to mapping geologists and paleontologists in the field. They are excellent time boundary indicators because of their rapid rate of evolution and world-wide distribution in the marine sedimentary record.
Ammonites and nautiloids lived together until the extinction event that killed off the dinosaurs, along with 75% of all life on earth, at the end of the Cretaceous period. This was when most all of Mississippi, and the much of the coastal plain of our neighboring states was covered in a shallow tropical sea.
Nautiloids inexplicably survived the extinction event at the end of the Cretaceous while ammonites did not and in doing so they flourished in the recovering ecosystems of the oceans. Today, the Nautilus is the sole living shelled cephalopod swimming the world’s oceans.
Different depositional environments and their fossil assemblages, called “facies” by geologists, are recorded across the coastal plain of the Northern Gulf of Mexico.
Because of this, open marine to shallow marine deposits of the Paleocene can be best studied in neighboring Alabama, while the shallow marine to terrestrial facies from the same time period can be best studied right here in Mississippi.
For more on Mississippi’s geologic past:
Windows Into Mississippi’s Geological Past – MDEQ
As the State Geological Survey, our MDEQ Office of Geology’s geologists often work with a number of experts in a wide variety of fields as it relates to our state’s fascinating geology and its history.
This month our Surface Geology team has been working on a project to help describe and document an important ancient Native American artifact from Ferguson Mounds in Jefferson County, Mississippi.
This artifact was collected around 1900 by Dr. M. W. Dickeson and was featured on page 201 in our early Geological Survey report from 1926, titled: The Archaeology of Mississippi, by Calvin S. Brown. This landmark publication by our Survey helped to highlight the importance of preservation and documentation of our State’s extensive prehistoric history and ancient cultural resources. The zoomorphic effigy specimen was originally described as the broken half of an artifact called a banner-stone styled into a “frog like” form. There is much debate in the archaeological community on the exact function of banner-stones. Many are made from exquisite and exotic stone sources, but very uncommonly are they in the form of effigies and even rarer do they take on a zoomorphic form like this one.
The artifact now resides professionally curated in the collections at the Gilcrease Museum in Tulsa, Oklahoma but made its way to back Mississippi on temporary loan to the State to be studied by a team of scientists, including our Office of Geology staff.
Our Surface Geology division staff described the effigy as manufactured from is stone called siderite. It is an earthy iron carbonate mineral that forms in a variety of coastal plain environments in Mississippi. It is reddish-brown to almost black and forms as nodules of various shapes and sizes. It is typically much harder and denser than limonitic clay-stone, commonly used in other ancient Native American artifacts. Siderite can easily be polished and can exhibit a subconchoidal fracture when broken. Raw nodules of the stone can have a flaky weathering character if its surface but contains a more desirable competent harder core underneath.
Siderite nodules can be found in a number of the geologic settings in Mississippi. It is best known for its abundance in Mississippi River alluvial gravels. It can also be found in the muddy brackish water environments along the shores of Mississippi’s Gulf Coast and can be distinguished when diagnostic mollusk fossil impressions are present or have characteristic holes in them from pholad clam borings.
The specimen measures 44.5 mm tip of nose to break, 38.8 mm wide at break, and is 23.7 mm thick. The approximated hole diameter 12.4 mm.
New geologic detailed geologic mapping research has been published on the area by our Surface Geology division which aided in the understanding of the geologic setting of the site the artifact was recovered from along with the availability of natural stone resources to the area. The Ferguson Mounds site is situated atop a bluff consisting of loess-covered, nearly level, Pleistocene age first terrace of the Mississippi River. Gravel resources near the base of the terrace, containing an abundance of siderite, are exposed along the banks of Mississippi River from Jefferson County south through Natchez. Early geologic work refers to these exposures as the “Natchez Formation”.
From being able to study the stone material, in person, our geologists concluded that the raw material this bannerstone was crafted from is indeed derived from a Mississippi River gravel sourced siderite. It was likely acquired along the river in gravel exposures outcropping nearby the Ferguson Mounds site.
Research biologist from MDWFP’s Mississippi Museum of Natural Science were also included in the scientific team to help to describe the zoomorphic effigy banner-stone. Thought we will never really know what the artist had in mind, it seems to be similar to the form of a salamander than that of a frog as originally described in Calvin Brown’s Archaeology of Mississippi report.
The diagnostic features of the blunt snout, large dorsal orbital sockets (though the eyes themselves are comparatively small), head profile, slender crouching front legs, and unexposed gill slits beneath the jowls are not similar of a that of or frog as the artifact was originally described. It could be imagined salamanders were possibly quite mysterious to the artist’s world. A number of beautiful and interesting types salamanders are native to Mississippi and locally to the Jefferson County area.
In fact, one of the largest salamander’s in North America inhabits the rocky environments of the Tishomingo County area. This true giant of a salamander is in the family Cryptobranchidae, known commonly of as the Hellbender. These large salamander would have been more commonly encountered by other Native American groups farther away but their dragon-like appearance may have added to the collective lore of these mysterious creatures in the artist’s world.
More on Calvin S. Brown’s, Archaeology of Mississippi: Archeology of Mississippi – MDEQ
More on recent geological mapping in Jefferson County and the Ferguson Mounds: OF-334 Geologic Map of the Pine Ridge Quadrangle Adams and Jefferson Counties, Mississippi – MDEQ
Geology is the basis for the environment and a broad exposure to the natural world around us is an essential aspect of environmental education. It takes a deeper understanding of the different factors and interrelationships that affect our natural world to fully comprehend and appreciate its complexity. MDEQ’s Office of Geology Staff works with the MDWFP’s Mississippi Museum of Natural Science to help foster public awareness and stewardship of our natural resources to preserve these natural environments and to help make them sustainable for future generations.
This past week MDEQ’s Office of Geology Staff lead a fossil collecting field trip for the Natural Science Museum’s Summer High School Naturalist Field Camp. We brought the participants to Smith County to a fossiliferous limestone outcrop, dating back some 30 million years to what once was the bottom of the Gulf of Mexico. Here we studied in great detail the various depositional environments of the ancient sea floor and the remains of the animals that once inhabited them.
Featured in today’s Fossil Friday is inspiring paleontologist and Museum summer naturalist camper, Christian Ingram proudly displaying his discovery of a fossil of an articulated pelecypod shell of the genus Penopea. This excellently-preserved fossil mollusk is an ancient relative of the modern geoduck, found today on the Atlantic coast and harvested as a food source. Christian and the other campers were given a great lesson on the various coastal depositional environments and opportunity to collect fossils of the different types of ancient animals that once inhabited them.
After the initial fossil excursion through central Mississippi, the summer camp continued down to the modern Mississippi Gulf Coast to participate in a host of hands-on active research with various coastal scientists in different fields and environments. We hope that these experiences help to inspire the next generation of environmental scientists such as geologists, biologists, and paleontologists for the future preservation of Mississippi’s natural world.
Geology is the study of the earth and archaeology is the study of the remains of the human record on the planet. Having an understanding of both helps us to better document the natural world around us, its natural history, and the history of the human interaction with it.
This week in the field brought me back to an outcrop of the Catahoula Formation in Simpson County to photograph and take some measurements. MDEQ’s mapping geologists had discovered this very important upper Oligocene in age fossil locality while conducting routine geologic mapping about 15 years ago and registered the paleontological site as Mississippi Geological Survey Fossil Locality #155 for future research.
In the few short years leading up to the COVID pandemic, our geologists had put together a paleobotanical research team to study the entire Neogene in the coastal plain of the northern Gulf of Mexico. This team included a star lineup of researchers from our State Geological Survey, University of South Alabama, Smithsonian Institution, Delta State University, and the University of Southern Mississippi.
Shortly after our first major paper on the Hattiesburg Formation (https://palaeo-electronica.org/content/2019/2540-miocene-plants-of-mississippi), we tragically lost our macroflora (fossil leaf expert) Dr. Brian Axsmith during the first round of COVID. Our paleobotany research continued strong, but only focused on the Palynology (fossil pollen and spores).
Our team is once again in full force with Dr. Debra Stults picking up the research where Brian had left us. So our work this week brought us back to visit this site, our team had planned to work on next.
This fossil site geologically predates the Hattiesburg site we had published on. It is composed of a thick fossil leaf-rich shale layer protected from erosion and natural weathering by a hard ledge of Catahoula sandstone.
On a high hill immediately above the fossil site is a small historic cemetery dating back to the early 1800’s. The cemetery site is pretty early for the area and remarkably still well-maintained by the locals, which included a small flag recently placed on a Civil War veteran’s grave. Being curious geologists. we were also particularly interested in the type of stone usage/diversity/timing of the grave markers while visiting the fossil site.
Not surprisingly, the oldest grave markers in the cemetery were made from the local Catahoula sandstone, very likely acquired directly from the fossil site in the creek below. We could imagine that the fossil leaves may have also been noticed by these earlier visitors and may have been curious about them, too while salvaging the flagstones of sandstone from the creek.
The succession of gravestone from Catahoula sandstone was followed by imported marble in the later 1800’s, and then concrete leading into the Depression era, and ultimately by finely polished granite in the mid-20th century.
In the study of geology, a “Type Locality” of a geologic formation is the outcrop that it was first formally described and named by geologists. A formations Type Locality is often named for a nearby feature or landmark, typically the name of a creek or stream the outcrop is exposed in or even something like a close by town. The formation’s Type Locality outcrop is extremely important to geologist. The sediments, fossils, structures, depositional environment, and the stratigraphic position studied at a formation’s Type Locality are compared to other outcrops at the surface and in bore holes that penetrate similar strata in the subsurface. This information allows a geologist to properly correlate and accurately map the extent of geologic formation both at the surface and in the subsurface. When mapping the geology encountered in a region it is important to continually revisit and study formation’s Type Localities to gain this basic comparative scientific information.
Geology is the basis for the environment and that is why MDEQ’s Office of Geology, as the state’s geological survey, is charged with mapping the geology of the state. This information is essential for our state to properly understand, better conserve and protect, and manage its natural and economic resources. This includes mineral and groundwater resources, natural habitats, geohazards, and for land management (which includes private and municipal planning and development).
This week our mapping geologists revisited the Type Locality of the Byram Formation for ongoing detailed 7.5 min geologic mapping projects where other outcrops of the Byram formation are expected to be present and encountered. The Byram Formation is a fossiliferous marl (sandy fossil rich limestone) that was deposited in a shallow marine environment during a time known as the early Oligocene epoch, some 30 million years ago. The Byram Formation was named from an outcrop along the Pearl River underneath the historic Byram Swinging Bridge near the town of Byram in southern Hinds County, Mississippi.
The Byram Formation is the uppermost member of the Vicksburg Group that has been documented from Warren County across south central Mississippi, through Wayne County into south Alabama, and into the deeper subsurface throughout south Mississippi. It represents marine sediments from the last time the seas extended this far into Mississippi.
Today’s Fossil Friday features the fossil rich and scientifically important Type Locality of the Byram Formation. Photographed is the beautiful indurated marl exposures along the Pearl River at Byram, MDEQ geologist studying the outcrop, and a perfectly preserved fossil marine scallop shell (named Pecten byramensis) exposed at the outcrop. This field experience will prove invaluable to our scientists during the geologic mapping projects being conducted in central Mississippi over the coming months.
Fossils are essential for geologists to understanding past environments. These paleontological resources are how we piece together the details about the landscape and plants and the animals that once inhabited it.
As we discussed in last week’s Fossil Friday, MDEQ’s geologic mapping program (State Survey) has been studying a broad, flat, loess-covered terrace that stretches across western Jefferson County and south through Natchez, overlooking the Mississippi River. This terrace was left behind by the Mississippi River near the height of the last glacial maxima. As ice accumulated on the continent to the north, sea levels dropped dramatically causing the great river to cut a deeper valley and abandon its previous floodplain level, leaving the terrace behind. This drop in the river’s base level is was the creation of the Mississippi Delta Region as we know it today, bordered by the highlands of the bluffs.
Glacial flour from off of the newly-formed alluvial plain blew in as dust storms quickly capped the terrace upland in thick deposits of loess. This silt formed as ground rock from a mile-thick sheet of ice bulldozed and scraped the bedrock to the north. Loess soil is rich in minerals and well-drained. The basis for a lush ice-age habitat, safe from the episodic flooding of the river valley below.
The loess is also rich in calcium carbonate minerals making it ideal for excellent fossil preservation of the ice age animals that inhabited the region. We know from their fossils that extinct giants like the American lion, mastodon, mammoth, and giant ground sloths were common place here and that the first human inhabitants to Mississippi likely encountered and even hunted them and maybe even were hunted by them.
A particularly curious pig-like animal, the tapir, also called this loess-covered terrace environment its home. These large herbivores had a short snout that was prehensile like that of an elephant’s trunk. They were certainly numerous base on their relative abundance in the fossil record. Tapir still exist today in the woodland jungles of Central and South America but became extinct here in North America sometime towards the end of the last ice age around 11 to 12,000 years ago.
Humans entered the paleontological record in Mississippi at some point during the last ice age. The Native Americans that first arrived in Mississippi encountered an environment that would seem quite strange to us today. The plants of the forests and prairies would be more familiar in modern northern climates than to those of Mississippi today. The landscape hosted an even stranger variety of animals that are now long extinct.
Geology is the basis for the environment and is an integral part of archaeology. Geologic mapping is essential to understanding the age of landscapes and their paleoenvironment. It is also important for characterizing depositional environments and the geochemistries conducive to the preservation of these important archaeological resources. The tools that the first inhabitants left behind in Mississippi are the only evidence we have to study and learn about these first peoples’ relationship with that ancient environment.
The ice-age first people’s cultures are known collectively by the scientists who study them as Paleoindian. They were thought to be highly specialized and nomadic hunters of the late Pleistocene as evidenced by their exquisitely made tools and the scarce number of longer-term occupation sites that they left behind. The discoveries of most known early Paleoindian artifacts are happen-chance and made by landowners, collectors, and hobbyists, and not often by researchers in the field. This makes the general public, those who have found and collected these artifacts, the most important resource for information we, as scientists, have to study this earliest human time period in Mississippi’s prehistory.
Earlier this year, a Clovis point was found and brought to the attention of our Surface Geology staff. Clovis are the earliest recognized human artifacts found in Mississippi. This important discovery was made by Michael Carbon in his cultivated food plot overlooking the upper reaches of the Homochitto River in southwest Copiah County.
This excited our MDEQ, staff geologists because of their recently published research and detailed geologic mapping work they have conducted in the area. Michael’s Clovis artifact can reveal some very important clues about the ice-age people who lived in the area and their utilization of the resources in their environment.
Not too far to the west of where Michael’s Clovis was found, a broad flat loess covered terrace stretches across western Jefferson County and south through Natchez, overlooking the Mississippi River. Thanks to the work of our fossil collector friend, George Roberts, this expansive loess plain is also known to have once been home to an abundance ice-age wild game such mastodon, bear, horses, sloth, and tapir. But the ice-age hunter would have to venture east into rugged loess hills, away from this fertile plain for the essential stone resources for tool making.
The Michael Carbon Clovis demonstrates a familiarity of the important gravel resources in the Pre-loess Terrace Deposits found in the uplands of this loess terrain and the exquisite stone resources which they provide.
The Clovis artifact definitely originated from the loess bluffs area but was not actually found in either of these important resource-rich loess environments. It was found further to the east, just outside of the loess terrain.
The Michael Carbon Clovis was found along of the uppermost reaches of the Homochitto River in the southwest corner of Copiah County. An environment quite geologically and ecologically different than the loess region. Today it is a pine forest ecology with poor acidic soils. The geology of this region consists of cuesta capped with red sand and poor-quality gravel resources of the Pliocene age Brookhaven Terrace. Headwaters of streams in this area form from multiple springs as they emerge from the eroded perimeter of this gravelly terrain and expose the sandstone and clay of the underlying Miocene bedrock.
Because of the geology, the soils of the archaeological site the Michael Carbon Clovis was found on lend to very poor preservation of anything other than stone. We may never know exactly what resources this environment along upper reaches of the Homochitto provided that these first Mississippians were utilizing. But by being able to identify the rock source area it was manufactured from, we do know that the point moved along with these first inhabitants between these two very distinctly different ecological regions. As other artifacts may come to light from this archaeological site over time, a more complete, and likely more complex picture will emerge about the lives of our State’s first inhabitants during the last ice age.
More on the geology of the area that helped to tell this story:
OF-295 Geologic Map of the Rodney Quadrangle Jefferson and Claiborne Counties, Mississippi – MDEQ
OF-299 Geologic Map of the Union Church Quadrangle Jefferson County, Mississippi – MDEQ
For over 300 million years of our earth’s history the worlds oceans were teeming with shelled cephalopods, called ammonites and nautiloids. These diverse groups of predatory mollusks are relatives of modern octopus and squid. They swam and hunted in both shallow marine waters and the open seas. Species of these strange creatures ranged in size from fractions of an inch to true sea monsters with shells larger than 8 feet and diameter and likely weighing more than a thousand pounds.
Today ammonite and nautiloid shell fossils are highly-prized by collectors. These iconic fossils have distinctive radiating patters (called) sutures that range from simple in nautiloids, to amazingly complex fractal patterns in ammonites. Their shells were constructed of beautiful mother-of-pearl. This fossil shell material is also prized today as an iridescent gemstone, called “ammolite”.
Ammonite and Nautiloid shell fossils are very important to mapping geologists and paleontologists in the field. They are excellent time boundary indicators because of their rapid rate of evolution and world-wide distribution in marine sedimentary record.
Ammonites and nautiloids lived together until the extinction event that killed off the dinosaurs at the end of the Cretaceous period. Mississippi was covered in a shallow sea at that time. Therefore, we can best study this time period right here in outcrops in what is now northeast Mississippi. Fossil finds of these shelled cephalopods are quite common across much of the Black Prairie and Pontotoc Ridge regions of the state along with a wealth of other fossil remains.
Todays Fossil Friday features a large specimen of the fossil nautiloid, Eutrephoceras. It was collected by MDEQ Office of Geology staff from an outcrop of the Late Cretaceous Ripley Formation in Union County, near Blue Springs Mississippi. Large dinosaur bones and ammonite fossils were also found at this site where this nautiloid was collected.
At the end of the Cretaceous period a meteorite struck the Gulf of Mexico, killing 75% of all life on earth. This included all of the non-avian dinosaurs on land and all of the ammonites in the worlds oceans. Nautiloids however, did survive this catastrophe, specifically Eutrephoceras. Because of this, the Nautilus is the sole shelled cephalopod swimming in the world’s oceans today.
Click here for more on Mississippi’s Late Cretaceous Geology.
This is important addition to our scientific study of Mississippi’s natural history and research on the Late Cretaceous Period of North America. This volume has numerous detailed color photographs of the beautifully and amazingly well-preserved fossil mollusk shells. During the days of the Dinosaurs northeast Mississippi was once covered by a tropical shallow sea and these fossils represent part of that ancient ecosystem.
Some of the specimens figured for this project now reside in the collections of our national museum, the Smithsonian. The Mississippi Geological Survey has continued this important work since it’s founding in 1850 as Mississippi is home to some of the most significant paleontological resources on the planet. Hard copies are available through our publications and map sales. To find out more about our MDEQ, Survey Library’s online publications follow the link below.
To Download a free digital copy, click here.
To order a hard copy for $20, click here.
Pleistocene fossil remains from the giants of the last ice of extinct beasts such as mammoths, American lion, giant bison, mastodon, saber toothed cats, horses, giant ground sloths, tapir, gomphothere, pampather, and dire wolves that once hunted and grazed along the prairies of what is now northeast Mississippi. Surface Geology staff joined the paleontologists from Mississippi Museum of Natural Science and the MCWain Science Center in identifying a new fossil find this week. The amazing find of associated bones of the bear-sized giant ground sloth made, Megalonyx jeffersonii, was made earlier this week by USFWS biologist, Dr, Luke Pearson while conducting a freshwater mussel survey with his team in Noxubee County, Mississippi. The enormous bones consisted of well-preserved portions of the pelvis, an almost a complete ilium and part of the ischium. MMNS paleontologists George Phillips identified the animal as an extinct ground sloth, MCWain Paleontologist Jun Ebersol further described it as the remains of very large male, MDEQ geologist James Starnes ascertained that the skeleton was found in situ and likely right where the sloth’s carcass came to rest and was deposited in the stream which will warrant further investigation by scientists of the fossil site. Dr. Pearson (pictured with his find) has donated the specimen to the museum where it can be further curated for future studies.
MDEQ Office of Geology staff have been visiting a geological and paleontological playground in Smith County, Mississippi for years. The Smith County Lime Pit has been a useful window into the Lower Oligocene Series and specifically the Vicksburg Group. The Lower Oligocene encompassed a time period from 34 million years before present to 28 million years before present. The formations that are present for this time period in the strata at the Smith County Lime Pit are the Forest Hill, Mint Spring, Marianna Limestone, Glendon Limestone, and the Bucatunna. These formations represent one of the last great sea level rises in Earth’s history. The Forest Hill represents a deltaic environment that was followed by the Mint Spring, Marianna, and Glendon when a shallow tropical sea covered this area. The Buccatunna occurs last in this sequence representing the fall in sea level and a deltaic environment once again.
Our geologists working jointly with the Mississippi Museum of Natural Science in the field near Aberdeen, MS encountered something truly strange back in June of 2007. A 90 million year old, partially petrified (silicified) log from the late Cretaceous period Tuscaloosa Formation being feasted on by living termites!
HOW COULD THIS EVEN BE POSSIBLE?!
One of the most common questions our MDEQ, State Geological Survey geologists get asked is “how long does it take for something to fossilize?” This is a really great question, but the answer isn’t that simple but always surprises folks. It is also quite nuanced and takes a bit of explaining to really understand.
First of all, fossils are the remains of plants and animals preserved in the geologic record. “Fossilization” typically refers to the mineral replacement of things like bone, teeth, shells, or wood by turning them to stone. Fossils and fossilization (mineralization) aren’t at all necessarily the same thing. Mineralization of a fossil or “fossilization” occurs through geochemical processes that are not dependent on a particular amount of time, but more specifically dependent on the environment.
Mississippi is known by many scientists to have some of the best preserved fossils in the world, going all the way back to the last days of the dinosaurs, like our fossil wood featured in today’s FossilFriday from late Cretaceous period. This is because many of our fossils are not actually fossilized (mineralized) which preserves exquisite and rare details about the fossil not seen anywhere else. This means that they are actually still composed (all or in part) of their original organic materials, even though they can be many millions of years old.
Fossil shells, bone, teeth, and even wood that have not been altered by mineralization are extremely important to our scientists. They hold important detailed information about things like the life, diet, and even the environment of a long extinct species of plant or animal. This kind of biological data is completely lost in mineral-replaced fossils.
This termite-infested fossil log from the days of the dinosaurs is a great example of understanding fossils and fossilization. Due to the chemistry of the geologic setting of this fossil log, some parts of it underwent mineralization that replaced it with silica minerals, while other parts remained perfectly preserved. The original wood being enjoyed like a well-aged fine wine by the termites that encountered it. This is just another amazing observation encountered by the work of our scientists in the field. (Photos courtesy George Phillips, MMNS).
Gravel fossil hunting is a state-wide pastime in Mississippi enjoyed by people of all ages. Whether it’s a young child sorting through the gravel for geologic treasures on the playground at recess or the curiosity of an adult picking up a rock that caught their eye out in their driveway, it is often the first introduction to paleontology for most folks here.
Our chert gravel deposits in Mississippi eroded from ancient limestone bedrock sources north of here, up in the mid-continent, and were brought down and deposited by rivers as they once crossed the coastal plain on their way to drain into the Gulf of Mexico.
Patterns of Mississippi’s chert gravel were created by the abundant fossils remains of ancient Paleozoic era sea creatures (hundreds of millions of years old) and continue to spark the curiosity of our local rock and fossil hunters and folks of all ages today.
For our geologists these gravel fossils are an important tool for studying the geologic history of these gravel and the shifting bedrock areas of these ancient drainages that brought the gravels down here over time.
Featured today in this Devonian Stromatoporoid fossil from the gravels of the ancestral Mississippi River Pre-loess Terrace Deposits in Warren County, Mississippi collected during field work with the University of Mississippi earlier this month. This particular specimen demonstrates the exceptional detail that can be preserved in these ancient fossils in our gravel.
Stromatoporoids were reef-forming sponges from the Devonian period (some 400 million years ago). They are found here exclusively among the gravels of ancestral Mississippi River Pre-loess Terrace Deposits, beneath the loess along the western bluff line overlooking the Mississippi River Delta region, from Memphis to south of Natchez. Their natural presence and abundance in these Pre-loess Terrace gravels helps to mark a geologic shift in drainages of the exposed bedrock sources in the upper reaches of the Ohio River Valley region during glaciation of the mid-Pleistocene some 700,000 years ago.
Geology Staff collected gravel samples in Warren County with the University of Mississippi geology doctoral student Maxwell Pizarro. Max’s primary focus of study is on igneous rocks.
Mississippi is a coastal plain state and all of our geology at the surface is sedimentary in origin. Therefore igneous rocks only occur at the surface here in sedimentary environments, such as a constituent of our gravel deposits.
Only two geological deposits contain igneous gravel rocks. One is the modern Mississippi River alluvium that underlies the Yazoo Basin in the Mississippi Delta region. The other is in the gravels of the ancestral Mississippi River Pre-loess Terrace Deposits which lie perched high above the delta along its eastern valley wall, beneath the thick loess deposits in the Loess Bluff Region.
Max worked with us earlier this week (over his spring break) in sampling our diverse collection of volcanic rocks from the Pleistocene gravels of the Pre-loess Terrace Deposits in western Mississippi. These rocks included extrusive rocks called rhyolite, trachyte, and volcanic tuff.
This week he also went to the field with our geologists to study and sample outcrops of the Pre-loess Terrace gravels in Warren County. His study for this project will be to help describe and source these volcanic rocks to their bedrock origins, some of which are over a billion years in age.
This valuable information will help our scientists mapping the geology of the area understand the dynamics of the evolution of Mississippi River in the lower valley over the course of its glacial history during the Pleistocene.
While conducting field studies for geologic mapping, our MDEQ, survey geologists often find evidence that we are not the first people to visit these, often remote, outcrops. Pictured below is a prehistoric Native American artifact, a crude biface (approximately 18cm in length) that was observed while studying a geologic outcrop in Yazoo County, Mississippi. It exhibits heavy use-wear from preferential battering along one edge. This artifact was fashioned from silicified fossil palm (Palmoxylon), from the Early Oligocene, Forest Hill Formation. Fossil Palm was prized by the early Native American inhabitants for it unique texture and beauty.
30 Million year old fossil pollen and spores samples were taken recently from a lignite bed at this outcrop for palynology study and paleoenvironmental reconstruction of these ancient deposits. This same geologic layer also bears large-diameter root bulbs of these fossil palm stumps, and the artifact was presumably a product of reduction of these silicified stumps for lithic material procurement, representing the evidence of an ancient mining practice. Stone tool artifacts made from fossil palm are well-documented from nearby prehistoric sites along the Yazoo River and likely originated from this and other nearby outposts.
A poster on this paleobotanical research on the plant fossils we collected from the Forest Hill Formation was given recently at both the Botanical Society of America and last month at the Mississippi Academy of Sciences on the details of our findings. This work was authored by a collaboration between Delta State University, the Smithsonian Institution, and MDEQ, geologists with the State Geological Survey.
A detailed geologic map, including the aspects of the paleontology and geoarcheology of the area is due to be published by our office this July through a cooperative mapping grant with the United States Geological Survey’s StateMap program.
What was it like millions of years ago? We can study the fossil bones, teeth, and shells of long extinct animals, but how do scientists know what rest of the details to make a picture of what the world they once lived in, so long ago, looked like? Our researchers at MDEQ’s Office of Geology frame that picture with the multifaceted research involved in what they do in geologic mapping projects. Geology not only provides information about our natural resources and provides the foundation for the environment that currently inhabits it, studying it also is our window into the environments of the deep past. This week MDEQ’s Surface Geology mapping staff field checked outcrops of the Forest Hill Formation for newly-drafted geologic maps soon to be published on Cox Ferry area of Yazoo County, Mississippi. The Forest Hill Formation consists of alternating sands and clays from formed in a coastal delta some 30 Million Years Ago. It us sandwiched between the deep marine clays of the Yazoo Formation below and the shallow tropical Vicksburg Limestone above. Further to the south (down-dip), these same are buried deeply by younger geologic formations, There, these sands act as an important fresh groundwater aquifer for the citizens of state and these outcrops we are mapping serve as the aquifer recharge areas for this essential natural groundwater resource. Along the bedding planes, photographed at one of these ancient outcrops off of Cox Ferry Road, a hash of lignitized fossil plant remains was studied this week by our field staff. We know from previous studies that fossil palm (Palmoxylon) dominates the silicified wood found here that once made up the forests along the riparian environments bordering the ancient river delta, but our research team has been learning much more. Office of Geology staff has been collaborating with paleobotanists and palynologists from Delta State University and The Smithsonian Institute to study and photograph the wealth of exquisitely-preserved fossil pollen spores to gain a more complete picture of the plant diversity and the paleoenvironment of the Forest Hill Formation.
If you look very carefully along the nature trail behind the Mississippi Museum of Natural Science, as you descend in elevation from the bluff to the Pearl River swamp, you will begin to notice that there are sea shells everywhere. These are not modern shells brought in with the gravel for the trail but fossils eroding from the bluff. They are from an ancient sea bed from a time long ago called the Eocene Epoch, almost 40 million years ago. The reason this bed of sea shells (called the Moody Branch Formation) are pushed up and exposed there has to do with a much more ancient story, from a much more ancient time. Buried much deeper beneath the Museum is the apex of a large volcanic structure, dating to the days of the dinosaurs during in the Cretaceous period, some 75 million years ago. This was once part of a string of volcanic islands (much like the Hawaiian islands today) that stretched from Jackson, through the Mississippi Delta, and into Arkansas. Please do not collect the shells, because this scientifically important outcrop is part of a Mississippi State Park. Just know their story, appreciate the local geologic history, and please share it with others.
This week, MDEQ Office of Geology research staff conducted a brief field study with museum’s Paleontology program’s George Phillips, Dr. Ezat Heydari faculty of the Earth Sciences program at Jackson State University, and were accompanied by high school student intern Nolan Wells who was job-shadowing with us this week. Featured photo of the week are a collection of perfectly preserved fossil mollusk shells of two specimens of Turritella alveata (Conrad in Wailes, 1854), Lapparia dumosa exiqua Palmer, 1937, and Carycorbula densata (Conrad in Wailes, 1854).
Mississippi has been well recognized by scientists throughout the world and by our own residents as having a wealth of geological resources, especially when it comes to our fossils. Fossils can tell us a great deal about the age and past environment of rock units in Mississippi, so much in fact, they are essential to interpreting our state’s geology.
While fossils from ancient marine environments are often the subject of detailed studies in Mississippi, those from terrestrial environments are just as equally plentiful but still poorly documented and understood. Marine fossils are dominated by the remains invertebrate a vertebrate animals while terrestrial environments chiefly consist of remains of fossil plants.
MDEQ’s Office of Geology’s ongoing collaboration with paleobotanists at Delta State University, University of Southern Mississippi, University of South Alabama, and The Smithsonian Institution are starting to open up a world of new knowledge of our past terrestrial environments with detailed studies of fossil plant sites in Mississippi. These studies have traditionally focused on fossil pollen and leaf fossil studies, but fossil wood in particular have received less research attention.
Fossil wood can be found throughout the state from the Paleozoic times (before the days of the dinosaurs) to the Pleistocene (the last Ice Age). Though much of it may look similar, it isn’t remotely the same stuff. Each formation it occurs in represents a different time period with a different ecology and different species of fossil plants, including trees. The study on fossil wood is very difficult and it is only done by a handful of very specialized scientists. Because of the wealth of fossil wood in Mississippi, we are beginning to reach out and work more with these specialists to open up a world of understanding to what the trees and forest were like throughout geologic time in Mississippi.
The photo features features an exquisitely preserved piece of silicified wood collected on a canoe trip from the Wolf River in Harrison County by Rep. Manly Barton, Mississippi House of Representatives District 109. It is likely derived from the Pliocene age outcrops of the Graham Ferry Formation which outcrop along the stream. This fossil wood is from a tree that grew in an ancient river delta, some 5 million years ago. The forests in this environment existed just before the onset of the Ice Ages of the Pleistocene.
The preservation of this fossil wood specimen is so detailed it is termed “permineralization”, a scientific term meaning that individual structures of the plant including things like the cell-wall can still be observed.
Some 20,000 years ago during the height of the last glacial maxima in the latter part of the Pleistocene ice age, the Mississippi River drained an ice-gripped landscape far to the north down through what is now Mississippi. Summers brought dark muddy floodwaters down the ancestral Mississippi River as the ice fronts melted back slightly, to then return to a dusty dry floodplain landscape as the next winter and ice returned. High winter winds created large dust storms across the Mississippi River valley and deposited glacial silt along the uplands in Mississippi from Memphis to Natchez and as far east as Hinds County in Mississippi. This silt was ground from the bedrock up north by the flow of ice. This created what is known as the Loess Bluff Region overlooking the Mississippi Delta Region today. The thick mineral-rich loess soils supported a lush temperate ecosystem of grassy plains along older river terraces uplands and hardwoods along stream bottomlands that dissected the region. Megafauna such mammoth, mastodon, giant ground sloths, saber toothed cats, tapir, giant bison, horses, and American lion roamed the area. While more discretely in the grass and forest leaf litter millions of pulmonate gastropods (land snails) thrived along the ground in this thriving ice age environment. Their fossil shell remains are the most abundant and best preserved of any ice-age fossil found in Mississippi. Theses snail shells are around 20,000 years old and perfectly preserved in the loess as if they were deposited yesterday. This specimen was photographed in Natchez last month by Office of Geology staff conducting field geologic mapping for the National Park Service.
Smith County’s geology is crossed by narrow narrow band of limestone hills containing the fossil remains of shallow sea. The band of limestone of the geologic formation called the Vicksburg Group, stretches east from Vicksburg, crosses HWY 18 in Smith County near the Jasper County line, on through Waynesboro, Mississippi.
It is a 30 million year old, extremely fossiliferous geological feature that contains the remains of an entire shallow marine ecosystem that once inhabited what is now central Mississippi from a time called the Early Oligocene epoch.
The limestones are rich with the remains of mostly fossil invertebrates such as mollusks, bryozoans, echinoids, crabs, and foraminifera. It also hosts an amazing variety of vertebrate fossils such as sea turtles, excellently preserved fish, sirenians, rays and sharks…lots of shark teeth!
The Vicksburg Limestone host a great diversity of sharks fossils, both of large and small species. In fact, fossil teeth from Carcharocles auriculatus, one of the largest sharks to ever inhabit the earth have been discovered at these rock outcrops in Smith County.
Featured this week is an excellently preserved fossil echinoid (relative of a sand dollar) named Clypeaster rogersi, from the Mint Springs member of the Vicksburg Limestone. It is surrounded by abundant fossil seashells of the scallop named Pecten byramensis. It was photographed during joint fieldwork being conducted by Office of Geology Staff and other researchers.
Field studies help our scientists understand and familiarize themselves with the geology of the state and study how it related to the stratigraphy and geological history, the environment, mineral and groundwater resources, and to natural and wildlife ecosystems.
Mississippi’s unique geology is endowed with extremely rich fossil deposits. Many of these treasures adorn local personal collections and professional collections in museums across the globe. Though the interest in Mississippi’s geology by collectors and scientists is mainly in these excellently-preserved fossil specimens, our State’s gravels have been regularly combed since ancient times for beautiful stones such as agates, carnelian, jasper, clear quartz, and petrified wood. A Mississippi tradition that today is still held by many rock-collecting enthusiasts. But until recently, no known precious gemstones have ever been discovered in Mississippi.
About a hundred years ago in neighboring Louisiana, a small-scale deposit of gem-quality opal was mined. This occurred in the Flemming Formation of Vernon Parish along the Texas border where a small deposit of vibrantly colored matrix was discovered cementing sandstone into hard quartzite. This opal was once sold directly to Tiffany’s Inc. in New York City and fashioned into gemstones.
Field mapping by the Mississippi Geological Survey in Claiborne County in 2004, has led to the discovery of another precious opal deposit in the South. This time from the Catahoula Formation of Mississippi. This rare occurrence is even more spectacular than the one found in Louisiana.
The research leading to this amazing discovery was conducted under a cooperative geologic mapping grant between the United States Geological Survey and the State. The raw stone material was initially tested for gem quality by the Mississippi Gem and Mineral Society’s expertly skilled craftsmen. The exquisitely-crafted stones show beautifully brilliant flashes of opal fire, ranging in color from green to red.
The discovery of this site is very sensitive, not only for the precious gem-quality opal it contains, but also because of the signs of pre-historic Native American activity associated with the outcrop. This includes opalescent quartzite artifacts! A number of other quartzite-bearing outcrops have been discovered mapping in south Mississippi. Therefore, it is entirely possible that other outcrops may also contain gem-quality Mississippi Opal.
Cauliflower chert geodes, also commonly referred to as “Keokuk geodes”, can commonly be collected from our Pre-loess Terrace gravels and from gravel bars along the Mississippi River. They are typically lined with quartz crystal druse or botryoidal chalcedony, while some examples grew solid and lack a geode cavity. They originated from Paleozoic bedrock limestones in the upper-reaches of the Mississippi River and its tributaries and were carried down here to Mississippi as a constituent of gravel. Many of these cauliflower chert geodes once originated as ancient fossils, such as calyxes crinoid, that became the nucleus for silica mineral growth from fluids within the limestone. The fossil became badly distorted by the growth of chalcedony and remained hollow inside until mineral-rich waters deposited quartz growth along the walls of the badly distorted fossil. The resulting cauliflower chert eroded from the bedrock limestone, leaving pits along its surface where the remaining fossil piece dissolved out. Figured in stages, is this geologic process of cauliflower chert formation recorded in crinoid calyx examples collected from Paleozoic bedrock, along with two cauliflower chert geodes from the Pre-loess Terrace gravels from Mississippi. The last two examples were photographed from Mississippi gravel. The first (stage 4 photo) was collected from Yazoo County and latter, in-situ on the banks of the Mississippi River by MDEQ, Office of Geology staff in Natchez. Special thanks to Rebecca Thea Davis for providing the bedrock fossil examples from Tennessee.
Our chert gravel deposits in Mississippi eroded from ancient limestone bedrock sources north of here, up in the mid-continent, and were brought down and deposited by rivers as they crossed the coastal plain on their way to the Gulf of Mexico.
Patterns of Mississippi’s chert gravel were created by the abundant fossils remains of ancient Paleozoic era sea creatures (hundreds of millions of years old) and spark the curiosity of our local rock and fossil hunters and folks of all ages today. This undoubtedly has also been the case for people here more than 13,000 thousand years.
Towards the end of the last ice-age, the indigenous population of Mississippi first utilized these abundant fossil-bearing chert gravels as a primary resources for tool manufacturing. On literally a daily basis, over the course of thousands of years, these first people’s cultures encountered these patterns created by these fossils preserved in the stone that a familiarity with these gravel fossils surpasses any of today.
Figured in this post is a good example of this in an artifact called a flake, a sharp spall created during a lithic tooth manufacturing technique called flint-knapping. It was collected from a Woodland cultural period site (500BC-1000AD) in a plowed agricultural field by Olivia Anderson in Yazoo County. This example is littered with well-preserved fenestrate bryozoan fossils that were identified in the artifact by Office of Geology staff.
Bryozoans are colonial animals similar to corals but are unrelated. Fenestrate bryozoans can easily be identified by their delicate lace-like structures. These ancient Bryozoans first appeared in the fossil record during the Carboniferous and went extinct during the Permian period (345-268 million years ago). They are one of the most common fossil occurrences amongst our chert gravels.
So what were the stories and traditions about these fossil that the person that made this artifact had? Undoubtedly, this person had an intimate knowledge and an encyclopedic cultural understanding of these gravel resources, as did generation after generation before them in making literally millions of tools from these native geologic resources.
More on our gravel fossils:
Rocks And Fossils Found In Mississippi’s Gravel Deposits – MDEQ
Towards the end of the last ice age, the area that is now the Mississippi’s Loess Bluff region was a strange place some 20,000+ years ago. Frequent dust storms in the Yazoo Basin brought massive amounts of glacial silt off the Mississippi River floodplain. It came down the river from glacial meltwater floods, blown off the surface once dry, and deposited into the adjacent eastern uplands. These thick loess soils are very rich in minerals and nutrients and were quickly vegetated in the moister climate of the bluffs. Several species of giant ground sloths once inhabited this area and thrived eating the lush vegetation in the loess bluffs. They were true gentle-giants. Their fossil bones, such as this exceptionally well-preserved claw found by last month by William Pettis in Yazoo County and identified by Office of Geology staff, are a testament to this lost world from the ice-age in Mississippi’s Loess Bluff region.
Specimens of siderite (an iron carbonate mineral) are among the most common rocks brought in off the Mississippi River for identification. They are unusually heavy for their size and range in color from black to red-orange and typically exhibit very shiny polish on the surface of the stone. They are often mistaken for a variety of things such as meteorites, fossil bones and teeth, and even dinosaur skin impressions due to their wide range of unusual shapes, sizes, and textures. Siderite forms naturally from the geochemistry of the groundwater of the Mississippi River’s alluvium. This mineral can indeed replace (mineralize) organic materials such as fossil bone, wood, and apparently even mollusk shell by occupying tiny pore spaces of these organic materials. One particularly interesting specimen was brought into the Museum of the Mississippi Delta by Laura Sanford during a fossil road show in late October in Greenwood. It was identified by at the special program by Office of Geology staff as a rare occurrence of a Pleistocene age, siderite-replaced freshwater mussel shell from the alluvium of the Mississippi River. This unusual ice-age mollusk fossil was collected on the Louisiana side of the Mississippi River in East Carroll Parish. Geology staff identified it as Potamilus purpuratus, also commonly known as Bluefer or Purple-shell mussel, aptly named for its distinctive beautiful purple color mother-of-pearl of this species, which still inhabits many rivers in Mississippi and Louisiana today. The excellent presentation of this fossil freshwater mussel exhibits both valves of the shell still articulated (attached) in typical mussel death position (shell open).
This week, just minutes after MDEQ’s Surface Geology staff Jonathan Leard successfully defended his masters thesis at Mississippi State University on the first detailed geologic map of the Starkville area, he was found studying an important and newly exposed geologic outcrop just off of campus. Here he explains to MSU freshman anthropology student, Abigail Starnes the important geologic contact that is represented in the fresh excavation. The lighter-colored rock unit below, is a limestone called the Prairie Bluff Formation. It from the Late Cretaceous period and is chock full of marine sea shell fossils that were some of the last things alive in the ocean just before the meteorite struck the earth that killed off the dinosaurs some 66 million years ago. The darker-colored deposits above the limestone are significantly younger and are from the late Pleistocene. It contains the fossilized remains of extinct ice-age land animals that the first people in North America and the first Native Americans to arrive here in Mississippi would have encountered. The contact between these two geologic units is called an unconformity because it represent missing time between the two formations. In this case, a hiatus of tens of millions of years, which can only demonstrated by studying the abundance of different fossils contained between the two geologic units at this outcrop.
The current near historic low of the Mississippi River has it’s dry banks exposing miles of seemingly endless sandbars that are now, once again, sharing its ice-age secrets from the river’s depths. Pleistocene fossils from extinct beasts such as American lion, giant bison, mastodon, saber toothed cats, horses, giant ground sloths, tapir, gomphothere, pampather, and dire wolves that once hunted and grazed along the forests and wetlands of the Mississippi River floodplain have now been exposed along the now barren river bottoms. Surface Geology staff joined the Mississippi Museum of Natural Science and USFWS scientists this week along the banks of Mississippi River in Warren County to help understand and to better document these important paleontological resources during this unique environmental opportunity.
During this field trip an important discovery of a fossil of an ancient bear-sized rodent, a giant beaver called Castoroides ohioensis, was made by biologist Paul Hartfield during the trip. Paleoindian cultures, the first human inhabitants of Mississippi, likely shared their environment with this and other strange Mississippi ice-age beast.
Additionally, a larger ice-age Mississippi River bottomland ecosystem was documented during the study which included fossils of giant catfish, gar, turtles, alligators, giant bison, deer, elk, mastodon, mammoth, and horse. These fossil specimens will be accessioned into the Mississippi Museum of Natural Science paleontological collections for public display and for scientific study.
As the glacial climate ended and the environment rapidly changed along the Mississippi River at the close of the Pleistocene, the ice-age megafauna gradually became extinct. People persisted along the great river and they, along with the ecosystem began to adapt to a world that we are more familiar with today.
The first people, to inhabit the Mississippi’s Northwest Delta region towards the end of the last ice age lived in quite an unfamiliar world than that of today. It was once thought that this area, known today as the Yazoo Basin, was an environment called as “braided stream”, a formidably unstable landscape that would have been largely uninhabitable by these first people known as Paleoindian cultures.
This idea was only just recently dispelled by research that identified numerous Paleoindian archaeological sites and used it to date landforms within the Yazoo Basin. This important research was published on by a team of scientists from the Office of Geology and the L.B. Jones Trust. The L.B. Jones Trust is an important archaeological and paleontological collection housed at the Museum of the Mississippi Delta for the preservation of Mississippi Delta history and scientific research. View the Office of Geology publication here.
As glacial ice was making its final retreat into the arctic, these ice age Paleoindian hunters here in the lower Mississippi River valley encountered a bounty of wildlife along the meanders and back swamps of the great river. Familiar to these first people of the Delta were animals such as American lion, giant bison, mastodon, saber toothed cats, horses, giant ground sloths, and dire wolves that hunted and grazed along the forest and wetlands of the Mississippi River floodplain. As the climate rapidly changed at the close of the Pleistocene and the megafauna gradually became extinct, people in the Delta during the Early Archaic cultural period adapted to their surroundings.
Remains such as fossil bones and teeth of these extinct ice-age beasts that once inhabited the Delta can still be found along the gravel bars of the Mississippi River today. Featured in this week’s fossil Friday is the portion of a fossil jaw from bear-sized ground sloth, Paramylodon harlani, commonly known as Harlan’s ground sloth. It was collected in Washington County, Mississippi by L.B. Jones Trust chairman and researcher, Anna Reginelli and identified this week by Office of Geology Staff.
As geology is the basis for the environment, geology staff is often involved in multidisciplinary research with other agencies and institutions. Yesterday, Geology staff assisted the Mississippi Museum of Natural Science conservation biology team in a freshwater mollusk survey being conducted on the Pearl River in Marion County. During Thursday’s survey, State Ichthyologist, Robbie Ellwanger discovered a bone from a very large turtle amongst the gravel in the river. The bone was identified by geology staff in the field as an ice-age fossil turtle and the specimen was collected for study. Vertebrate fossils from this part of Mississippi are very rare and are essential to our understanding of the geologic history of the area. Once the team returned to the museum, Paleontologist George Phillips further identified the fossil bone as a piece of a large alligator snapping turtle shell. This find is a first for the area, making it an important contribution to the fossil record.
The alligator snapping turtle (Macrochelys temminckii) is the largest species of freshwater turtle in North America. Individuals of this icon reptile can live over 100 years and grow to be more than two hundred pounds. The family that includes these turtles goes back to the days of the dinosaurs during the Cretaceous period. Very little is known about alligator snapping turtles in the fossil record and most material available for study comes from ice age river and swamp sediments deposited during the Pleistocene. They are currently listed as a vulnerable species in need of conservation efforts. This important fossil specimen will be accessioned into the Mississippi Museum of Natural Sciences paleontological collections. There, it will help scientists to better understand the Pearl River’s ancient geologic past and will also help in studies of this living fossil in North America.
Mississippi’s wealth of well-preserved fossils have been studied by researchers from all over the world for more that two centuries. That tradition continues through to today as MDEQ,s geologist performs the work of Mississippi’s Geological Survey in studying the state’s natural resources and its natural history. The fossils contained in the various geologic deposits around the state hold important clues to past life, past climates, and past ecosystems. What our scientists learn has implications for not just here in Mississippi but also around the world. Fossils are important tools for geologists to help map geologic formations and to correlate rock units far beyond the boarders of the state. The scientific value of invertebrate fossils such as ancient marine mollusk shells are very important in this respect. Our State Geologist, Dr. David T. Dockery is an invertebrate paleontologist who’s research focuses specifically on studying, naming, and describing these important resources. Following recent publications on hid studies of fossil mollusks from the Late Cretaceous deposits of northeastern Mississippi, 27 holotypes of new fossil gastropod species were sent to the Smithsonian this month to be archived in the U. S. Natural History Museum’s collections.
This Late Archaic cultural period Native American artifact, utilized as hammer-stone, was collected off a prehistoric archaeological site by an oxbow lake near Satartia in Yazoo County, Mississippi. It was utilized sometime between 2,000 BC and 800 BC from a large Stromatoporoid chert gravel fossil.
Stromatoporoids were reef-forming sponges from the Devonian period (some 400 million year old). They are found among the gravels of ancestral Mississippi River Pre-loess Terrace Deposits, beneath the loess along the western bluff line overlooking the Mississippi River Delta region, from Memphis to south of Natchez. Their natural presence and abundance in these Pre-loess Terrace gravels helps to mark a geologic shift in drainages of the exposed bedrock sources in the upper reaches of the Ohio River Valley region during glaciation of the mid-Pleistocene some 700,000 years ago.
They are curiously absent from our older (pre-glacial) Pliocene age High Terrace gravels further east in south-central Mississippi. The occurrence of these chert fossils in archaeological context at sites has been observed broadly across the MS Delta Region and also, as far east of the bluff-line as Smith County in Mississippi. This helps demonstrate a relatively long distance prehistoric cultural trade of these high-quality, larger chert clast-size gravel resources that emanated from the Mississippi loess bluffs region, east into areas with limited and poorer quality available resources.
Special thanks to Jim House of the Mississippi Archaeological Association, Madison Chapter for allowing MDEQ, Surface Geology staff to identify and photograph this remarkable fossil artifact specimen.
Linked below is the MDEQ FossilFriday post from September 6, 2019 featuring another interesting stromatoporoid fossil culturally utilized as an ancient artifact. It is polished mano artifact collected from an archaeological site along the Leaf River in Smith County, Mississippi. This was found roughly 100 miles east from its original natural source in the Loess Bluffs. The use-wear exhibited on the mirror-like, highly-polished surface of the artifact exposed incredibly detailed features of the fossil’s mamelon and astrorhiza structures.
Click here to learn more about the Smith County Stromatoporoid Artifact Specimen:
The revelations garnered from our recent geological mapping work on the timing and evolution of the lower Mississippi River Valley, has lead to the development of a new framework to better understand the environmental effects of the cyclical glaciation on the lower Mississippi River valley and it’s geology. Our work has identified Pleistocene deposits containing a host of well-preserved flora, faunal, and even early cultural remains that have yet to be fully studied and relayed in their proper context.
Core samples were taken today during a drilling projects to study an uninterrupted stratigraphic section of an ancestral Mississippi River Pre-loess Terrace Deposits in Jefferson County, MS. This terrace is blanketed by more than 70 feet of loess cover, masking a perfectly-preserved paleosol and surfacial clay stratum from the alluvium of the ancestral Mississippi River during the last interglacial stage of the Pleistocene. This is just before the river abandoned this level and began cutting its present valley during the last glacial advance.
Radiometric dating of these core samples is planned and will necessarily benefit our stratigraphic understanding along. Palynological research for paleoenvironmental context will be done, as well.
Outcrops of this terrace have been described along the river in the early literature as the “Natchez Formation” but the extent and context of it has only been recently understood. We have mapped the extent of this level of Pre-loess Terrace from southern Claiborne to Adams County.
The expression of this loess-draped terrace surface is heavily dissected today by erosion. But during the last glacial episode, it hosted a lush broad and level prairie environment overlooking the Mississippi River and boarded to the east by the older aggressive uplands.
Thanks to the work of George Roberts, a host of well-preserved late Pleistocene Megafauna remains have been recovered from the drainages that dissect this feature along with artifact evidence of early habitation from Paleoindian and early archaic cultures. Undoubtedly this is just scratching the surface of what is preserved here.
Within the last few thousand years this feature has undergone erosion, but still was was considered ideal for habitation into the later cultural periods. Iconic archaeological sites such as Feltus Mounds, Anna Mounds, Windsor Mounds and Windsor Ruins are just a few of studied sites adorning the expression of this terrace surface. — with Paul Parrish and Jonathan Leard.
Geology is the basis for the environment and fossils are an important tool for our scientists that study Mississippi’s geology. These ancient clues provide us the necessary details to understand the age, depositional environments, and layered sequences that make up the geology of our state. Many people think of Mississippi’s fossils as the large ancient bones and numerous sea shells which can been found throughout the state. But many of the most important fossils we study can’t be seen with the naked eye. Billions of tiny skeletons of animals called foraminifera make up much of our state’s limestones and other marine deposits while tiny grains of fossil pollen and spores from ancient plants can be quite abundant and exceptionally well-preserved in many of our terrestrial deposits. Studying these sequences of alternating terrestrial and marine environments helps us to understand past climates and how it has changed over geologic time. While much work has been done on our marine fossils, comparatively little is known about these fossils from our terrestrial environments. Over the past decade, MDEQ’s Surface Geology and Mapping program has been collaborating with a number of universities and institutions to better understand these terrestrial environments and the fossil plants and animals they contain. This team includes researchers from Delta State University, The Smithsonian Intuition, University of South Alabama, Mississippi Museum of Natural Science, University of Southeastern Mississippi, and many others. Recent work has been focused on the plant fossil of the Lower Oligocene age Forest Hill Formation while sampling several outcrops during geologic mapping across the central part of the state. The contact between terrestrial Forest Hill Formation and underlying marine deposits of the Late Eocene age Yazoo Clay mark an important boundary in earth’s climate history, some 34 million years ago. The earth had been in a tropical greenhouse environment for tens of millions of years, going back to the days of the dinosaurs, and then suddenly began to cool at the close of the Eocene epoch. This climate shift is recorded in the fossils in both the Eocene and Oligocene age rocks of Mississippi and studying it is important to furthering our understanding of this time period. Preliminary research findings of the palynology (tiny fossil plant pollen and spores) from our sampling efforts of Forest Hill Formation were presented in a poster by our study’s lead author from Delta State University, Dr. Nina Riding last month at the Botanical Society of America’s conference in Anchorage Alaska. Surface Geology staff is proud to be a part of this research team. These collaboration efforts in various aspects paleontology continue to expand our understanding of Mississippi geologic past.
To learn more about Mississippi’s Geologic past here.
To learn more about Mississippi’s Cretaceous Geology here.
Do you have a rock or fossil that you want more information on? Click here to Ask a Geologist.
Humans entered the paleontological record in Mississippi at some point during the last ice age. The Native Americans that first arrived in Mississippi encountered an environment that would seem quite strange to us today. The plants of the forests and prairies would be more familiar to modern northern climates than to those of Mississippi today. The landscape hosted animals that are now long extinct such as mastodon, mammoth, giant beavers, ground sloths, horses, and giant bison. These animals were hunted by predators such as saber-toothed cats, dire wolves, and these first peoples. Lower sea levels exposed land far into the Gulf of Mexico miles beyond the barrier islands of today as evidenced by the Office of Geology Mapping in Jackson County, MS as well as an ice-age forest exposed by Hurricane Ivan in 2004, 60 feet beneath the Gulf of Mexico, south of Gulf Shores, AL.
Geology is the basis for the environment and an integral part of archaeology. Geologic mapping is essential to understanding the age of landscapes and their paleoenvironments, as well as characterizing depositional environments and the geochemistries conducive to the preservation of these important archaeological resources. The tools these first people left behind in Mississippi are the only evidence we have to study and learn about these first peoples’ relationship with their environment.
These ice-age cultures are known collectively as Paleoindian. They were thought to be highly specialized and nomadic hunters as evidenced by their exquisitely made tools and the scarce number of longer-term occupation sites that they left behind. The discoveries of most known early Paleoindian artifacts are by landowners, collectors, and hobbyists, and not made by researchers in the field. This makes the general public, those who have found and collected these artifacts, the most important resource for information scientists have to study this early time period in Mississippi’s prehistory.
On June 14, 2022, a very important discovery was made of an early Paleoindian point in Perry County, Mississippi by Matthew Sullivan, an artifact enthusiast and Circuit Court Judge for the 13th District of Mississippi while he was rock and artifact collecting with his friends. Realizing the significance of his find, Judge Sullivan brought it to the attention of the Surface Geology staff for examination. Retired archaeologist, Samuel Brookes consulted on the find during Judge Sullivan’s visit. The artifact was identified as a Clovis point making it approximately 13,000 years old. Geology staff identified the stone as a rare form of pure chalcedony not naturally occurring here in Mississippi.
Geology staff collected additional laboratory data on the point and consulted with geological surveys in nearby states to conclude the bedrock origins of the stone. The Judge Sullivan Clovis was manufactured from a type of pure chalcedony from agate replacement of fossilized coral. It is an extremely high-quality, translucent stone found only in Miocene and Pliocene age rock outcrops in Florida.
Geological resources naturally available to prehistoric cultures for stone tool manufacturing in the part of southeast Mississippi that The Judge Sullivan Clovis was found are scarce according to recent research published by Office of Geology staff. The discovery of The Judge Sullivan Clovis is important to science because it demonstrates the movement of people and material from east to west through south Mississippi during this ancient time in Mississippi’s ice age history.
Mississippi has a rich geologic past with a fossil record that includes a history in the Mesozoic era, also better known as the days of the Dinosaurs. Outcrops from the Late Cretaceous period underly the rich soils of the Black Prairie and uplands of the Pontotoc Ridge physiographic regions of northeast Mississippi. Much of these deposits were formed in warm tropical shallow seas teaming with life and now rich with their fossil remains. While the dinosaurs walked on land, giant marine reptiles and sharks ruled these ancient seas. Fossil bones and teeth of these animals are commonly found along an abundance of ancient sea shells from mollusks in most outcrops of Cretaceous age in Mississippi. The currents, waves, and storms along with scavengers tend to widely scatter these remains. Therefore, actual fossil skeletons of these animals are important and rare finds. Last month, Surface Geology staff partnered with vertebrate paleontology staff at the Mississippi Museum of Natural Science, to excavate an intact skeleton of a sea dragon, called a Mosasaur. The recent discovery was made by museum staff conducting fieldwork near Westpoint, Mississippi. This species of Mosasaur, known as Clidastes propython, is approximately 80 million years old. Though typically only isolated bones and teeth are ever found, this is the most common mosasaur found between the geologic units of the Tombigbee Sand and the Arcola Limestone at the top of the Mooreville Chalk/Formation. This find was in the middle part of the Mooreville Formation above an important geological mapping marker that can be traced a long distance, a fossil bed made up entirely of the extinct oyster called Ostrea falcata. The team managed to excavate portions of the skull (with teeth still intact) along with a number of vertebrae and some rib bones. This important specimen will be carefully reconstructed and curated for future study. #fossilfriday
During the last ice age, the prairie regions of northeast Mississippi were an environment that was a paradise for a host now extinct Pleistocene mammals and other ice age megafauna. Gently rolling grasslands were once broken by streams with broad alluvial plains boarded by bottomland forests. Saber-toothed cats, American lions, giant ground sloths, mammoths, mastodon, giant bison, giant armadillo, giant elk, giant tortoises, and even herds of horses once roamed this rich dark soils region. Paleoindian cultures, such as Clovis were among the first human inhabitants to Mississippi, some 14,000+ years ago, and were certainly witness to these great animals of long ago and exploited the bounty of this Mississippi ice-age ecosystem. Fossil bones of many of these extinct animals are commonly found in stream alluvium of the Black Prairie region of northeast Mississippi. Pictured is a large unidentified ice-age fossil mammal bone exposed along an outcrop of Pleistocene age stream alluvium that was encountered by MDEQ, Surface Geology staff while conducting field work this week in Clay County with the Mississippi Museum of Natural Science while studying the underlying Cretaceous geology bedrock. The natural weathering of these chalky limestones over the course of tens of thousands of years form the dark rich soils for which is the basis for this prairie environment.
The last days of the dinosaurs ended some 66 million years ago when a giant meteorite impacted the Gulf of Mexico and created a world-wide extinction event which instantaneously changing Earth’s environment, climate, and devastated ecosystems. As the work of the State’s Survey, research is being conducted by MDEQ’s Office of Geology staff this week in the Starkville area to map and delineate geology representing this time. This will be used to better understand this important time in Earth’s history, both before and after this event, which is best recorded in our geologic record in northeast Mississippi. Featured here are Late Cretaceous marine fossils from the Prairie Buff Formation that are being studied by our scientists from outcrops in Starkville area. Fossils from this time not only include the infamous dinosaurs, but also important invertebrate fossils, part of a once thriving diverse tropical marine ecosystem. This is represented in the Prairie Buff Formation by an abundance of giant extinct fossil oysters, clams, and snails that once inhabited the sea floor of the during the Late Cretaceous, just moments before the extinction event. #fossilfriday
Gravel fossils are many Mississippi folk’s (especially children) first exposure to paleontology. These ancient tiny fossil treasures can commonly be found along gravel roads and driveways, along creeks and streams, even on school playgrounds throughout much of Mississippi. Seven year old Fen Anderson, a budding geologist from Yazoo County, recently shared his discoveries with MDEQ, Office of Geology scientists. These tiny ancient sea creature fossils are of solitary rugose corals and crinoid stems from Paleozoic era, making them older than the days of the dinosaurs. His awesome fossil collection pictured here came from just one day’s worth of searching through playground gravel at Manchester Daycare. #fossilfriday
For more on collecting rocks and fossils from Mississippi gravel, click here.
Ichnology is a discipline of Paleontology that is the scientific study of tracks and trace fossils. Knowing what kinds of animals occupy certain depositional environments, the traces and tracks they leave behind, and an understanding of geochemistry help us to translate ancient geologic outcrops. This beautiful example was collected in Lauderdale County by Leslie Potter and sent to Office of Geology staff this week for identification through our “Ask a Geologist” online public outreach program. These excellently-preserved fossil decapod burrows are part of the Lower Eocene age Tallahatta Formation. This ichnofossils is named Thalassinoides and were made by numerous marine burrowing shrimp that once occupied a tropical sandy shallow sea floor that once occupied the east-central Mississippi area some 50 million years ago. They are preserved as stone casts from being naturally cemented with silica minerals that have now become harder than the surrounding sandstone so that they weather in relief. Because the chemistry of the sediments didn’t preserve any other fossils of marine life that once certainly occupied the area, these ichnofossils prove important to helping us understand the ancient depositional environment of the sandstones of the Tallahatta Formation. Every so often some rare fossil sea shell impressions have been found there but are extremely rare, whereas these Thalassinoides burrows are quite abundant. This one in particular is a pretty special find. The gassy-fill substance in the burrow is called Tallahatta Agate. It is a natural mineral formation of nearly pure chalcedony and opaline silica. Thank you again Leslie Potter for sharing your discovery with our geology research staff and allowing us to share it with others.
Click here to learn more about Lauderdale County geology
Ancient marine fossils, much older than the days of the dinosaurs can be found in chert gravels right here in Mississippi. This crinoidal chert (a type of rock that was once the sea floor dominated with the skeletal remains of fossil crinoids) from Jefferson County was photographed this week by Office of Geology staff. Complete fossils of crinoids are rarely preserved intact, though there individual segments and partial stems and calyx are some of the most common chert gravel fossil found in Mississippi. Crinoids are echinoderms, relatives of starfish and sand dollars and are still alive today in the worlds oceans. Paleozoic era chert gravel fossils from Mississippi can be found naturally though much of the state. They were once eroded from ancient limestone bedrock sources north of here, up in the mid-continent, and were brought down and deposited by by ancient rivers flowing to the Gulf of Mexico. Collecting gravel fossils are often the first exposure folks have to our rich paleontology resources in Mississippi. Crinoids are one of the many treasures to be found in our Mississippi chert gravels. Chert gravels is an important economic resource commonly used in many civil applications throughout Mississippi. So, gravel fossils can be found almost anywhere from playground, aggregate, to gravel roads and driveways, even in cement gravels along downtown sidewalks.
Click here for more information on Mississippi gravel fossils.
Calcite septarian nodules (commonly called dragon stones) are natural concretions of calcium carbonate that exhibit secondary mineral growth of yellow “dog-tooth” calcite along an intricate network of desiccation-like cracks. They make excellently beautiful mineral specimens, especially when they are carved, cut, and polished or as interesting curiosities if left natural. They typically form in impure, sandy, and fossil shell-rich limestones (called marls) from the geochemistry and movement of shallow groundwater. Groundwater moving through the marl formation derives carbonate minerals from dissolving and leaching from fossil sea-shells in the rock and concentrates it into a nodule. As the nodule solidifies to a hard rock it begins to shrink and a network of cracks form throughout the nodule. The voids created by the desiccation-like cracks then begin growing “dog-tooth” yellow calcite mineral precipitated from the carbonate-rich groundwater water. These nodules are much harder and more erosionally-resistant than the surrounding geologic formation they formed in. Therefore, they tend to weather in relief from the outcrop or completely weather out and can concentrate as unusually large bolder-gravels along stream beds that wind their way through the formation. Only a few geologic formations in Mississippi exhibit this phenomenon. Most notably is the early Eocene age Bashi Formation of east-central Mississippi in the vicinity of Meridian. Another example (photo below) of exceptional quality was recently documented by MDEQ, Office of Geology staff from the Late Eocene in age Moody’s Branch Formation while describing geologic outcrops in the field with in Yazoo County, Mississippi.
Click here for more on Mississippi’s Geologic past.
Ichnology, a discipline of Paleontology, is the scientific study of tracks and trace fossils. Knowing what kinds of animals occupy certain depositional environments, the traces and tracks they leave behind, and an understanding of geochemistry help us to translate ancient geologic outcrops. These excellently-preserved fossil decapod burrows where photographed in the field last week by MDEQ, Office of Geology staff. The fossil burrows were discovered eroding from an Eocene (Claiborne age) outcrop of the Creola Member of the upper Cockfield Formation exposed in the creek floor. They are preserved as stone casts from being naturally cemented with siderite, a distinctive iron carbonate mineral. Siderite commonly forms in shallow marine, brackish water, near-shore environments. With these clues found in the outcrop in the floor of the creek along with numerous seashell fossils it contains, it’s not hard to imagine a place very much like the Mississippi Sound today…shallow muddy water filled with burrowing crab and shrimp, as well as snails, oysters, and clams while drum fish, sea trout and flounder tail along the grassy shallows…but this is almost 40 million years ago, in a world filled with much more stranger beasts…and in Yazoo County, Mississippi. #fossilfriday
