Includes:
- sauropsida: reptiles and birds, which really are reptiles
- mammals, or if you want to include a bunch of extinct non-reptile mammal ancestors, synapsids.
Does not include amphibians. If you include them, you have the tetrapods.
When a characteristic is basal, it basically means the opposite of it being polyphyletic.
E.g. monotremes laying eggs did not evolve separately after function loss, it comes directly from reptiles.
It is quite mind blowing that this is polyphyletic on mammals and birds, what can't parallel evolution achieve??
Includes:
- amphibians
- amniotes, which includes:
- sauropsida: reptiles and birds, which really are reptiles
- mammals
The exact relationships between those clades is not very clear as there's a bunch of extinct species in the middle we are not sure exactly where they go exactly, some hypothesis are listed at: en.wikipedia.org/w/index.php?title=Tetrapod&oldid=1053601110#Temnospondyl_hypothesis_(TH)
But at least it seems rock solid that those three are actually clades.