Are Dinosaurs Reptiles ?

[Rishi]

(03-30-2020, 05:04 AM)Kingtheropod Wrote: Reptiles in them selves are not really as close as some may think. There is a lot of grey area. For example, lizards are actually more closely related to snakes then they are to turtles or crocodiles. Crocodiles on the other hand believe it or not are actually more closely related to Birds then they are to Snakes. Both crocodiles and snakes are classified as reptiles, yet they aren't as closely related to each other as they are to other types of animals. 

*This image is copyright of its original author

https://news.ucsc.edu/2014/12/crocodile-genomes.html

Thank you for saying about that grey area!
I once wondered about the positioning of that 1st green split & did some research... Fascinating stuff.

Turns out there is actually good chance that Mammalia originated from amphibians, or amphibian like species of earliest reptiles. The pre-mammals evolved directly alongside Reptilia. 

Dimetrodon was more related to mammals than reptiles, belonged to a group called "Non Mammalian Synapsids" or "Mammal Like Reptiles" (distinction was indeed much blurred back then). Later Synapsids/Therapids or mamalian reptiles were closest related to it.
From them the first proper mammal came in early Cretaceous 50-75 million years before the first avian birds, basically direct descendants of theropods, a lineage of dinosaurs.

*This image is copyright of its original author

Reply