A 260-million-year-old fossil species found in South Africa's Karoo basin provides a long-awaited glimpse into the murky origin of turtles, scientists say.
Researchers have described the extinct reptile, named Eunotosaurus africanus, as the earliest known branch of the turtle tree of life.
"Eunotosaurus is a critical link connecting modern turtles to their evolutionary past," said Gaberiel Bever, assistant professor of anatomy in New York Institute of Technology (NYIT) College of Osteopathic Medicine.
"This is the fossil for which science has been searching for more than 150 years. You can think of it as a turtle before turtles had a shell," said Bever.
While Eunotosaurus lacks the iconic turtle shell, its extremely wide ribs and distinctively circular torso are the first indications that this fossil represents an important clue in a long unsolved mystery: the origin of turtles.
Bever and his colleagues from the Denver Museum of Nature and Science, Yale University, and the University of Chicago described how the complex anatomy of the Eunotosaurus skull houses convincing evidence of the creature's important role in the deep history of turtle evolution.
The study was published in the journal Nature.
