No Mutants Allowed

Every last bird on earth come from a single common ancestor, anchored far into "advanced" bird evolution. Ostriches, for example, are not closer to Ostrich-like dinosaurs, and chickens do not represent any closer relationship than say ducks or crows.

The fixation on T-rex in dino-to-bird-transition is also entirely misguided, and based on pop science short-cuts, as Tyrannosaurids did not at all evolve flight, and only a *single* branch of Theropod went the bird-route. We are always talking about single points of evolution branching out.

This means, not even Velociraptor *led to* birds (especially since Velociraptor lived 70 million years ago, and first flight evolved about 150 million years ago, more than double the age!)
Instead, birds evolve from something *very similar* to Velociraptor, from the mid-late Jurassic. All birds! And no T-rex.

That post belongs in the dinosaur thread.

I'll probably bring it up again in the future :v It's a bit of a pet peeve, and one paleo-peeps on twitter were discussing in a thread, pop-science has made the overly specific 'T-rex-to-chicken-analogy' into a commonly held belief among the public.

But T-rexes were fluffy and fat like giant turkeys!

WELL, Tyrannosaurid family is bracketed well within feathered Theropods, and early smaller forms were fluffy, up untill the 6-7 metre size range, where later giant forms appear to be naked/scaly.

(In another random fun fact - despite reputations, the Tyrannosaurid family mostly consists of small to medium lanky-legged, long-snouted oddballs, sometimes with crests and stuff. T. rex belongs to a later advancement of bulky, stubby-legged, tiny-armed giants)

But did they have the thing with the exposed jaw muscle like in Jurassic Park or was that just to make them look evil on the movie?

The visible jaw-muscle is based on crocodile/alligator anatomy. It has indeed been popularized mostly by paleo-artists of the 80s and 90s, like Greg Paul who also hugely influenced the movie. Theropods could very well have had protruding jaw-muscles similar to a crocodile, but most dinos would have well developed cheeks and skin hiding all that stuff.

Were they cute dino cheeks?