Scientists lift lid on turtle evolution

May 16, 2012
The turtle is a closer relative of crocodiles and birds than of lizards and snakes, according to researchers who claim to have solved an age-old riddle in animal evolution.

The turtle is a closer relative of crocodiles and birds than of lizards and snakes, according to researchers who claim to have solved an age-old riddle in animal evolution.

The ancestry of the turtle, which evolved between 200 and 300 million years ago, has caused much scientific squabbling -- its physiology suggesting a different branch of the family tree than its genes do.

"The of turtles has confounded the understanding of ," the scientists wrote in a paper published Wednesday in the Royal Society journal Biology Letters.

Until the latest study, that is -- which claims to have been the biggest of its kind.

"Our study conclusively shows that the genetic story is that turtles are more closely related to birds and crocodilians," research team member Nicholas Crawford from Boston University told AFP.

Anatomy and fossil studies of turtles and their reptilian relatives generally place the shelled creatures in the family of lepidosaurs -- snakes, lizards and tuataras (rare lizard-like animals).

, however, say they have more in common with crocodiles and birds -- which fall into the archosaur group of animals that also included the extinct land-bound dinosaurs.

The latter finding has now been confirmed by the most exhaustive genetic study on the topic ever done, said Crawford -- having gathered "ten times as much" information as previous research efforts.

The team compared the DNA of the corn snake, the African helmeted turtle, the painted turtle, the American alligator, the , the tuatara, the chicken, the and the Carolina anole lizard.

Crawford said the historic confusion partly arose because turtles shared key physical characteristics with lizards, snakes and tuataras -- including a three-chambered heart. They had little in common with crocs and serpents.

Lepidosaurs and archosaurs share a common reptilian ancestor.

Explore further: New species and surprising findings in the Mariana Trench

add to favorites email to friend print save as pdf

Related Stories

Oldest sea turtle fossil unveiled in Mexico

Mar 06, 2009

Paleontologists on Thursday unveiled the oldest fossil remains of a sea turtle that lived 72 million years ago in northern Mexico, the National Institute of Anthropology and History (INAH) said.

Genealogy of scaly reptiles is rewritten

Nov 23, 2005

Penn State scientists have completed the most comprehensive analysis ever of genetic relationships among snakes, lizards, and other scaly reptiles.

Recommended for you

A vegetarian carnivorous plant

19 minutes ago

Carnivorous plants catch and digest tiny animals in order and derive benefits for their nutrition. Interestingly the trend towards vegetarianism seems to overcome carnivorous plants as well. The aquatic carnivorous bladderwort, ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Vendicar_Decarian
1 / 5 (1) May 16, 2012
This article has application to the The New American Century.

http://assets.diy...dles.jpg

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.