Thursday, January 14, 2010

Tawa hallae

Tawa hallae is a newly discovered basal therapod from one of the quarries on Ghost Ranch in New Mexico's Late Triassic Chinle beds, from about 213-215 million years ago. He's an interesting little critter, because he really makes a case for a more complex scene in dinosaur evolution and dispersal than was previously thought. Frankly, the entire Late Triassic has been growing in complexity over the last few years, with the discovery of the revueltosaurs, the silesaurs, and others.

Tawa has some features that are similar to slightly earlier Herrerasaurus, and others that are more similar to neighboring Coelophysis, who is the poster child of both the Ghost Ranch quarries, and early dinosaurian radiation in general. The unusual thing is that Tawa wasn't particularly closely related to its neighbors, which means the diversification of early dinosaurs must have happened really early, and to some extent, before they spread geographically very far from northwestern Argentina where they first appeared.

Anyway, I've attached the image of Tawa that seems to be ubuiquitous across the web. Enjoy.

1 comment:

Joshua said...

Y'know, it occurs to me that that's a fairly bold artistic interpretation there; a feathered basal therapod. The idea that all dinosaurs might have been feathered seems to really be growing in the general, mainstream consciousness.