Life in the Paleocene – the period that came right after the devastating K-Pg extinction that signaled the end of the Mesozoic – was mostly small and generalist. One of the resourceful survivors of the mass extinction was the newly described turtle Inaechelys that inhabited the coast of what is now northeastern Brazil around 62 million years ago.
This small chelonian’s ancestors probably survived the catastrophe by being small and eating whatever it could.The turtle also offers some clues about what was going on at the time. Though it was found in saltwater deposits, it is not related to modern sea turtles. Its closest living relatives are freshwater species, like the Amazonian river turtles.
The fact that it was not as adapted to life in the seas suggests that it could have eventually been outcompeted by actual sea turtles that were already present at the Paleocene.