Earliest fossil sea turtle

The earliest-known species of fossil sea turtle is Desmatochelys padillai, which existed more than 120 million years ago, during the early Cretaceous Period. Its first-known remains had been disinterred at Villa de Leyva in Colombia, South America, during the 1940s, but it was not until 2007 that better, additional remains were uncovered, which led to it finally being confirmed as a distinct species in its own right, and following further study it was formally described and named in 2015. It was similar in overall appearance to modern-day sea turtles but was bigger than an average human, measuring approximately 2 m in length.

Prior to this species' recent taxonomic recognition, the earliest fossil sea turtle known to science had been Santanachelyx gaffneyi, dating back 110 million years to the Cretaceous, and originally known only from a 20-cm-long fossil excavated in 1998 from the Santana Rock Formation in eastern Brazil. Unlike the digits of modern-day fossil sea turtles, which are entirely enclosed within flippers, those of this archaic species were distinct and moveable. It was named in honour of turtle palaeontologist Dr. Eugene S. Gaffney.