New 'Tree of life' puts turtles next to dinosaurs

Refuting the notion that turtles are most closely related to lizards and snakes, researchers from the California Academy of Sciences have now reconstructed a detailed "tree of life" linking turtles to dinosaurs.

Using a next generation sequencing technology, authors now place turtles in the newly named group "Archelosauria" with their closest relatives: birds, crocodiles, and dinosaurs.

Scientists suspect the new group will be the largest group of vertebrates to ever receive a new scientific name.

"New genetic sequencing technique called Ultra Conserved Elements (UCE) improve our ability to help resolve decades-long evolutionary mysteries, giving us a clear picture of how animals like turtles evolved on our constantly-changing planet," said Brian Simison, director of the California Academy of Sciences' Center for Comparative Genomics (CCG) that analysed the study's massive amount of data.

The new technique allowed scientists to move beyond years of speculation and place the Archelosauria group in its rightful place on the reptile tree of life.

The findings also resolve an evolutionary mystery surrounding softshell turtles - a bizarre group of scale-less turtles with snorkel-like snouts.

Until now, studies linked softshell turtles with a smaller semi-aquatic group called mud turtles - despite the fact that softshells appear in the fossil record long before their mud-loving counterparts.

The new findings place softshells in a league of their own on the evolutionary tree, quite far removed from any turtle relatives.

"The new 'tree of life' is consistent with time and space patterns we have gathered from the fossil record. These new testing techniques help reconcile the information from DNA and fossils, making us confident that we've found the right tree," noted study co-author and renowned turtle expert James Parham.

The results appeared in the journal Molecular Phylogenetics and Evolution.