Re: Follow-up: the truth about killer dinosaurs

[Michael Mortimer <mickey_mortimer111@msn.com>]

T. Michael Keesey wrote-

> I'm going to go on a little rant here. Nothing personal?it's just that
> I've heard this *so* many times.
>
> I get tired of hearing this excuse for artists to maintain the
> "classical" view of tyrannosaurid integument. There's no fossil
> evidence for _Ichthyornis_ having feathers, or _Patagopteryx_ or
> _Gargantuavis_ or _Rahonavis_, but no artist would dream of seriously
> restoring any of them as scaly.

And I'm going to go on a little counter-rant. ;)

Rahonavis preserves quill nodes on the ulna, so actually does preserve 
direct evidence of feathers.
Both Rahonavis and especially Ichthyornis preserve numerous morphologies 
indicative of flight - elongate wings, troissal canal, large sternal keel, 
and so on.  Bird flight requires feathers, so this is strong indirect 
evidence for feathers.
There's nothing about (comparatively) small flightless birds like 
Patagopteryx and Gargantuavis that leads to questioning the presence of 
feathers.  However, we know that tyrannosaurids were at least partially 
scaled.  Large mostly hairless mammals tend to keep hairs for functional 
reasons (eyelashes, tails for swatting insects, etc.).  Besides display, 
remiges and retrices would appear to have very limited potential function in 
tyrannosaurids.  Some flightless birds keep theirs for display (ostriches), 
some don't (emus, kiwis).  Who knows if tyrannosaurids would have?

Mickey Mortimer