We have reached the end of Paleo-Animal Fest celebrating the animals that populated the Cretaceous seas of Arkansas 65-120 million years ago. We have seen early crocodilians and gars. We have seen the largest of the predators in the ocean and some of the smallest of creatures populating the seas. Today we are going to wrap it up with an animal famous the world over: elasmosaurs.
A spectacularly preserved vertebra from an elasmosaur found in southwest Arkansas.
Nessie. Surgeon’s photo. Not an elasmosaur, not even a real animal
Many people today will not know them by that name, but show them a picture of Nessie, the Loch-Ness Monster, and the image they conjure up is the classic elasmosaur, a long-necked marine (which is funny because Loch Ness is a freshwater lake) reptile with big flippers and a small head, essentially looking like a predatory aquatic sauropod. Of course, it probably didn’t hold its head way out of the water like shown in most imaginings, but the general appearance is close.People are frequently pulling things out of the ocean and claiming they are long-lost Mesozoic Monsters from the time of the dinosaurs. Of course, they always wind up being something else.
Basking shark. Not an elasmosaur
Sadly, elasmosaurs died out the same time the big dinosaurs died out.But they had a good run, first appearing in the Triassic, close to the beginning of the Mesozoic Era. Elasmosaurs were part of a group called sauropterygians, which first appeared over 200 million years ago.
This is an elasmosaur
Here are a couple of illustrations of elasmosaurs. One is by my son, which will be appearing in a booklet I am making about Arkansas during the Cretaceous, as well as a coloring book for kids I am putting together. Some of them really did have amazingly flexible, ridiculously long necks.
Here is one in the expected habitat and following expected behaviors.
Come back next week to celebrate Arkansas Cretaceous Shark Week.
paleoaerie 
Great post. I have a colleague in Colorado who is dying to dig one of these guys up.
Best,
Chase
Thanks! I would love to find one myself. I have run across the occasional vertebra of a mosasaur, which is cool, but I have yet to find a good specimen containing a flipper, much less a skull. All the elasmosaur material in the state has been scrappy, like this vert, but there have been several decent mosasaurs found. Unfortunately, they were almost all found almost 100 years ago and have been destroyed or lost. There remains very little of what used to be here. So I am hoping something more turns up. And, as always, hoping someone around here finds more dinosaur than the current half of a foot and a whole lot of tracks.
[…] dinosaurs. Mosasaur vertebrae are not uncommon, although the skulls are. More rarely, one can find plesiosaur (the article only mentions elasmosaurs, which are a type of plesiosaur, but most plesiosaur […]