Proganochelys is the oldest turtle species discovered to date, known only from fossils found in Germany and Thailand in strata from the late Triassic, dating to approximately 210 million years ago.

In life it was about 1 m long, its overall appearance resembling modern turtles in many respects: it lacked teeth and had the characteristic heavily armored shell, formed from bony plates and ribs which fused together into a solid cage around the internal organs. There are some notable differences compared to modern turtles, however: Its long tail had spikes and terminated as a club, its head could not be retracted under the shell, and its neck was protected by small spines.

Because of its generally advanced characteristics, however, most biologists feel that Proganochelys, while the oldest known turtle, is almost certainly not the oldest turtle species.

External links

• http://www.amnh.org/exhibitions/expeditions/treasure_fossil/Fossils/Specimens/proganochelys.html
• http://www.enchantedlearning.com/subjects/dinosaurs/glossary/indexp4.shtml

Prehistoric reptiles | Turtles | プロガノケリス