Crocodiles are some of the most fierce ambush-predators in the world. There are only 24 crocodilian species around the world and seven are considered Critically Endangered by the international Union for Conservation of Nature and Natural Resources. Now, a team of scientists have mapped the crocodile family tree, including their extinct relatives called Pseudosuchia. The family tree is detailed in a study published December 4 in the journal Nature Ecology & Evolution and offers insight into the role that the environment has historically played on crocodile evolution.
[Related: Why scientists gave vaccines to farmed crocodiles.]
Ruling reptiles
Crocodiles and birds share an evolutionary heritage with dinosaurs and pterosaurs, despite there being 11,000 living bird species compared to only 24 crocodile species. Crocodiles are the only living members of a mostly extinct clade called archosaurs or “ruling reptiles.” Archosaurs date back to the Early Triassic, about 251 million to 200 million years ago.
Archosaurs belong to a group called Pseudosuchia, which includes multiple species that are more closely related to crocodiles than they are to birds. Pseudosuchias went extinct at or before the Triassic–Jurassic extinction event about 201.4 million years ago. However, one group called the crocodylomorphs, survived the major extinction and gave rise to the crocodiles.
“The fossil record is a rich source of valuable information allowing us to look back through time at how and why species originate, and crucially, what drives their extinction,” study co-author and University of York biologist Katie Davis said in a statement.
In the study, a team of researchers used the fossil record to build a large
Read the full article here