What is the reptilian ancestor of lizards, snakes, crocodiles, dinosaurs, and birds?

Question

What is the reptilian ancestor of lizards, snakes, crocodiles, dinosaurs, and birds?

Answer 1

perhaps a perodactyl

Answer 2

Browse the tree of life web project:

http://www.tolweb.org/tree/

One thing you should be aware of.  Since these different groups diverged over 100 million years ago, their last common ancestor may not resemble any species now living, and even if it does, the contemporary version will itself have been evolving in the meantime.

Answer 3

The answer to this question goes way, way back to before the time of the dinosaurs. Since all life is thought to have evolved from a single common ancestor, there has to be a place in the tree of life where all of the species that you listed are together as one species. Crocodiles, dinosaurs and birds are all considered to be in the archosaur lineage and lizards and snakes are from the modern lizard lineage. There is a third lineage that led to mammals and a fourth that led to turtles and perhaps more but I can't remember right now. Anyway, all four of these lineages share a common ancestor from before the great Permian extinction, and this ancestor is usually referred to as the "stem reptile" and it was the first creature to have an amniotic membrane in its eggs. Our own human amniotic sac during our own pregnancy and development is derived from this common ancestor. This innovation, the amniotic cavity and membrane, allowed these first reptiles to cease being amphibians and live all of their lives on dry land. I was at the museum of Natural history in Washington DC and I saw a model of three lizard looking creatures that were labeled "stem reptiles". I hope this helps.

P. S. If you are interested in this sort of thing, please read the excellent book "The Ancestor's Tale" by Richard Dawkins and turn to the chapter titled "Reptiles".

Answer 4

What Sciencen...  said.

Answer 5

THECODNTIA

Answer 6

i dont think there is a reptilian ancestor according to the biological trees i've seen.  maybe either an amphibian grew scales or a fish evolved into a reptillian creature