Researchers just discovered a turtle fossil from 228 million years ago that doesn’t have a shell. Interestingly, the unique new species did possess a toothless break, which is a key turtle characteristic.
The new species is named Eorhynchochelys sinensis, which means “dawn beak turtle from China,” since it’s believed to be the first turtle with a beak. It also possesses a body in the shape of a Frisbee with wide ribs. However, these ribs did not contribute to the formation of the shell common in modern turtles.
“This creature was over six feet long, it had a strange disc-like body and a long tail, and the anterior part of its jaws developed into this strange beak,” said Olivier Rieppel, co-author of the study. “It probably lived in shallow water and dug in the mud for food.”
And since it was able to develop a beak prior to other turtles, the species is an example of mosaic evolution, which is when traits evolve independently and at different times.
“This impressively large fossil is a very exciting discovery, giving us another piece in the puzzle of turtle evolution,” said Nick Fraser, co-author of the study. “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.”
“With Eorhynchochelys’s diapsid skull, we know that turtles are not related to the early anapsid reptiles, but are instead related to evolutionarily more advanced diapsid reptiles. This is cemented, the debate is over,” Rieppel said. “Eorhynchochelys makes the turtle family tree make sense. Until I saw this fossil, I didn’t buy some of its relatives as turtles. Now, I do.”