Mammal-like reptile survived much longer than thought

[sauroid]

Fossils in Japan overturn widely accepted theory about tritylodontid extinction
https://www.sciencedaily.com/releases/2016/04/160425112655.htm

[Flaffy]

Cool! So some did survive after all

[PaleoMatt]

Wow! This is really cool!

[Megalosaurus]

Newbie question but anyway:
What are the key skeletal features that makes a tritylodontid differ from mammals?

[Nanuqsaurus]

I thought ''mammal-like reptile'' wasn't a valid term anymore? Because the ancestors of mammals weren't actual reptiles? Maybe it's just to make this article easier to understand, I can see why they'd do that. Nice article anyway, really interesting! I always wonder what more fossil suprises are waiting to be found.

[Halichoeres]

Newbie question but anyway:
What are the key skeletal features that makes a tritylodontid differ from mammals?

Tritylodontids retain some primitive aspects of the jaw articulation. The lower jaw, instead of being formed entirely from the dentary, retains the articular, which articulates with the quadrate in the upper jaw (rather than the temporal or squamosal as in mammals). They also lack canines, which of course some mammals also do, but it's another relatively distinctive feature.