“This impressively large fossil is a very exciting discovery giving us another piece in the puzzle of turtle evolution,” says Nick Fraser, an author of the study from National Museums Scotland. “It shows that early turtle evolution was not a straightforward, step-by-step accumulation of unique traits but was a much more complex series of events that we are only just beginning to unravel.”Additionally, features of the turtle’s skull indicate that it was part of the diapsid family of reptiles, which also includes modern lizards and snakes. Previously, scientists had wondered if prehistoric turtles instead belonged to the anapsid family.
“With Eorhynchochelys’ diapsid skull, we know that turtles are not related to the early anapsid reptiles, but are instead related to evolutionarily more advanced diapsid reptiles,” states another of the study’s authors, Olivier Rieppel of Chicago’s Field Museum. “This is cemented, the debate is over.”
Eorhynchochelys, incidentally, is Latin for “dawn beak turtle” (as in the first beaked turtle), while sinensis means “from China.”
The study, which also involved scientists from the CAS Center for Excellence in Life and Paleoenvironment, and the Canadian Museum of Nature, is described in a paper that was recently published in the journal Nature.
(Sources: Field Museum, Nature via: https://newatlas.com/prehistoric-beaked-shell-less-turtle/56037/)