A team of paleontologists has found in China the fossil remains of an ancestor of turtles that roamed our planet without a shell 220 million years ago. The animal, contemporary with the dinosaurs, has been baptized asOdontochelys semitestacea (toothed, half-shell turtle).
Their finding seems to answer one of the greatest mysteries of reptilian evolution:how the shell and body of the turtles developed. Chun Li, from the Chinese Academy of Sciences, explains today in the magazineNaturethat, although the ancestral species did not have a shell on its back, it did exhibit aplastron-the lower flat part that protects the stomach- fully developed. Analyzing its structure, they have come to the conclusion that the complete carapace was formed when the spine and ribs developed outwards, and later extended until they merged on the animal’s back. The process would be similar to what is currently observed during the early development of modern hatchlings within the egg.
On the other hand, paleontologists suspect thatOdontochelys semitestaceait was asea animal, so I needed the plastron toprotect yourself from predators while swimming.
The discovery ofOdontochelysdisplaceProganochely, another reptile ten million years younger found in Germany that until now was considered the “grandmother” of all turtles.
