Turtles More Closely Related to Birds Than Lizards and Snakes, Genetic Evidence Shows
ScienceDaily (May 23, 2012) — The evolutionary origin of turtles is one of the last unanswered questions in vertebrate evolution. Paleontological and morphological studies place turtles as either evolving from the ancestor of all reptiles or as evolving from the ancestor of snakes, lizards, and tuataras. Conflictingly, genetic studies place turtles as evolving from the ancestor of crocodilians and birds. Having recently looked at more than a thousand of the least-changed regions in the genomes of turtles and their closest relatives, a team of Boston University researchers has confirmed that turtles are most closely related to crocodilians and birds rather than to lizards, snakes, and tuataras.
The researchers published their findings in the Royal Society journal Biology Letters. By showing that turtles are closer relatives to crocodiles and birds (archosaurs) than lizards, snakes and tuatara (lepidosaurs), the study challenges previous anatomical and paleontological assessments. Nick Crawford, a post-graduate researcher in biology in BU's Graduate School of Arts & Sciences and lead author of the study, achieved these findings by using computational analysis to examine regions of the different animals' genomes.