Re: [Re: Feathered/scaly theropods: trying to make the point.]

["David Marjanovic" <david.marjanovic@gmx.at>]

 

If feathery integumentary structures where added later on due to vagaries of
the process of fossilation? Then we should have found also some other groups
of "feathered" fossils (e.g. frogs). But so far only (nonavian) dinosaurs and
birds where found with such.

Several nondinosaurian diapsids (Monjurosuchus, Hyphalosaurus) as well as AFAIK Psittacosaurus from the same sites have preserved scales.

Another point, how would you explain that the integument of birds where
preserved correctly, while that of (nonavian) dinosaurs wasn't?

In my last e-mail I forgot to add that AFAIK the feathers of Liáoníng birds and near-birds look the same (haven't seen specimens), and that even the feathers on the various pieces of "Archaeoraptor" are genuine!

 

Concerning secondary featherlessness and tyrannosaur scales -- what about a single mutation that produced scutes all over the body instead of only on the feet?