this is coelophysis (by jeff martz). he's one of the first dinosaurs, in the mid-to-late triassic. he shows all of the hallmarks of the things that differentiate dinosaurs from other sauropsids and even other archosaurs at the time. but more interestingly, he shows a lot of the hallmarks of modern birds. his bipedal posture (the thing that makes dinosaurs fundamentally different than lizards like the tuatara, and even other archosaurs like crocodiles) is one of those thing. he balances his weight over his hips, which are somewhere between those of a crocodile and a bird. he almost certainly had feathers. and he even has hollow bones (his name means "hollow structure") like a bird. this is one of the earliest dinosaurs.
I avoided commenting on the bolded bit before, because I thought it was wildly off topic, but admin just reminded me that this is in Free for All, so fuck it.
'Almost certainly' is vastly overstating the case. It's controversial exactly where feathers arose in dinosaur evolution, but we do have preserved scaly skin impressions showing that not all dinosaurs were completely covered in feathers; and in at least one case an entire mummified dinosaur excellently preserved that shows no sign of feathers anywhere. There are a couple of examples of integument in ornithischian and sauropod dinosaurs which have been suggested to be primitive feathers, but this is controversial.
Coelophysis is a theropod, but a very early theropod. Every clear example we have of feathers from the fossil record is from a coelurosaurian theropod, and Coelophysis lies outside that clade. It might have been feathered, but at the minute that's just speculation. Feathers might be a synapomorphy of Coelurosauria.
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