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Re: Bird origins tied to oversized muscles and lack of brown fat



 "A developmental biologist at New York Medical College is proposing a
 new theory of the origin of birds, which traditionally has been
 thought to be driven by the evolution of flight. Instead, Stuart A.
 Newman, Ph.D., credits the emergence of enlarged skeletal muscles as
 the basis for their upright two-leggedness, which led to the
 opportunity for other adaptive changes like flying or swimming.

See, that's actually about the origin of dinosauromorphs, not that of birds.

So often, it is claimed that when neontologists talk about "birds", they mean the crown group. This one means the total group.

 And it is all based on the loss of a gene that is critical to the
 ability of other warm-blooded animals to generate heat for
 survival.....".

What evidence is there that brown fat isn't a mammalian autapomorphy instead? Even if that neontologist still believes in Haematothermia, this doesn't makes sense as far as I can tell.