Oldest Known Sea Turtle Fossil Discovered In South America:
Paleontologists working in South America have described an ancient sea turtle as the key to understanding the turtle’s murky evolutionary history, and it is at least 25 million years older than any other known sea turtle fossil.
Edwin Cadena of the Senckenberg Naturmuseum in Germany and James Parham of California State University Fullerton unveiled a new species of a nearly two-meter-long marine turtle in the latest issue of PaleoBiosnamed Desmatochelys padillai from the Lower Cretaceous (120 million years old) of Colombia that sheds light on the mysterious origins of marine turtles and their confusing relationships to living sea turtles.
Until the local amateur paleontologist, Mary Luz Parra and her brothers Juan and Freddy Parra discovered Desmatochelys padillai near Boyacá, Colombia, Santanacheyls gaffneyi from Brazil was the previous oldest fossil sea turtle record holder.
Now, this new species can be used to date the radiation of sea turtles and perhaps help figure out their origins, as it has recently been proposed extinct marine turtles are not closely related to living species like loggerheads and leatherbacks.
Fossils of sea turtles are quite rare and also difficult to identify in the fossil record, as the primary marine adaptations of modern sea turtles like enlarged salt glands do not get preserved in the fossil record.
Luckily, enough diagnostic morphological evidence from the skulls and front paddles of specimens of D. padillai have been preserved to firmly identify it as a member of a group of marine turtles.
D. padillai was large, about as long as a 6-foot tall human, but this does not make it anywhere close to the largest sea turtle ever.
The largest sea turtle that ever lived was Archelon from the Cretaceous of South Dakota, growing to the monstrous size of more than four meters long and almost five meters wide.
The largest living sea turtle is the leatherback, which is roughly the same size as D. padillai would have been.
Even at 6 feet long, D. padillai was still a potential meal, as one specimen has a shell with two deep bite marks in it, probably caused by a pliosaur.