Phylogenetic tree of tetrapod relationships with emphasis on extant groups. I posted this on my stories on IG last night and I had SO MANY messages of people who still thought mammals descended from reptiles and who are still surprised birds are dinosaurs! #paleoart #sciart

Things to take away from this tree:
1) Mammals did NOT descend from reptiles. They share a common ancestor with them but were never part of Reptilia. Mammals are synapsids. The term “mammal-like reptile” still so pervasive in popular media is wrong and misleading.

2) Lizards belong to a group called Squamata. Snakes are just one of the several groups of lizards that lost their external limbs. However they are just that, a group of legless lizards. For example, iguanas are more closely related to snakes than either of them is to geckos.

3) Crocodilians (crocodiles, caimans, gharials, etc) are the only extant members of a group that was hugely diverse during the Mesozoic and large part of the Cenozoic. Crocodilians are more closely related to dinosaurs (which includes birds) than they are to other reptiles.

4) Pterosaurs are NOT flying dinosaurs. Pterosaurs are the sister group to dinosaurs. There were/are flying dinosaurs and the ones alive today are called BIRDS.

5) Birds ARE dinosaurs. They are just a group of theropod dinosaurs, in the same way we humans are a group of primates.