Fossilized Vertebra identification

[MOGARDE]

Hello,

 

I am hoping someone can help identify this fossilized vertebrae that was found along the Missouri River near St. Louis, MO.  It is 2" across.

[val horn]

i see the round end and think croc, but want to know more about the geology of the site since i am completely unfamilar with the area and dont know what is possible.

[pachy-pleuro-whatnot-odon]

Identifying isolated vertebrae without any geological or depositional context is going to be very difficult, especially in absence of any diagnostic features. What can you tell us about the geology at the site where you found the specimen? What age are the sediments there? Are they terrestrial, lacustrine/riverine, or marine deposits?

 

A lot of vertebrae are not unique in their shape. However, based on what animal species are know to occur at a find locality, a likely candidate can often be put forward. And to have a guess at the types of animal that might have been present, we need to know chronology and palaeoenvironment. I agree with @10313horn that there is an argument to be made for crocodile, as the vertebra is elongate with a slight waist, as well as one concave and one convex side to the vertebra (though not very pronounced). But there are other animal species that have similar features, we don't know whether the concavity and convexity are over-interpretations, nor which side would've led off towards the head (i.e., whether the vertebra is procoelous or opisticoelous)...

 

[MOGARDE]

The site the fossil was found is a very large sandbar that was exposed due to the river level dropping lower than it has been in several years. In the past couple of weeks, we have found a fossilized (bison, horse, shark) tooth along with Native American artifacts and a few pottery sherds. We have found many fossils (crinoids, lepidodendron, brachiopods, horn coral, coral) and petrified wood and agate.  We love it when we can search the river because we can find anything since it flows through the Dakotas and Nebraska. I appreciate the information that you have shared so far as it has helped and I see now how it could be a crocodile.  I have included some information below on the history of our area and some animals found.  I understand that it may not be able to be accurately identified with the photos and once the virus situation gets better we could take it to a museum to see if anyone would be able to assist. I really appreciate the knowledge you have shared and the example of the vertebrae's.

 

Pleistocene epoch, glaciers intruded southward into Missouri, covering the region north of the Missouri River.  At that time mastadons were widespread in Missouri. A rare mastadon tooth is still occasionally found within couple of hours of us. Mastadon State Park is less than an hour away and is where skeletal remains were found. Mastodon remains were preserved in almost every county in the entire state. Mammoths were also present but left behind fewer fossils. Other Pleistocene mammals that once lived in Missouri include armadillos, bison, bears, camels, deer, horses, musk oxen, peccaries, porcupines, probable raccoons, sloths, and tapirs. A sinkhole near Enon in Montieau County preserved non-mammalian fossils of the age like frog and turtle bones.

 

Hypsibema missouriense is a type of dinosaur called a Hadrosaur or "duck billed" dinosaur. It was a herbivore with jaws that contained over 1,000 teeth. Hypsibema had evolved specialized teeth to handle the tough, fibrous vegetation of the time. Hypsibema lived in Missouri during the Late Cretaceous Period. Hypsibema was first discovered in 1942 by Dan Stewart, near the town of Glen Allen, MO, and became the state's official dinosaur on July 9, 2004

[pachy-pleuro-whatnot-odon]

Well, what you're describing here is what you'd call your classical palimpsest situation: material from different times all mixed together in an undisentaglable mess. For, with Nebraska - and presumable possibly the Niobara Chalk formation - in the mix, a procoelous vertebra might just as well belong to a mosasaur as to a crocodile (or even a plesiosaur for that matter, if we're misinterpreting the convex side and that side is actually flat).

 

The conservation of the vertebra doesn't strike me as particularly Pleistocene, but I don't think we could exclude that epoch just on that. Nor would it help us very much if we did...

 

I'm curious to see what others might have to say about this fossil.