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Re: MORE FEATHERS & NEKKID MAMMALS



Jeff Martz wrote (in response to Peter Buchholz):

>> T.rex didn't have a lot of other avian/_Archaeopteryx_ osteological
>> characteristics, so why are you assuming that feathers were were
>> among the SOFT ANATOMY traits shared with birds?

Actually, tyrannosaurids have a fair number of avian osteological
characteristics, even more so than Compsognathus.  Just because the tyrant
dinos were whopping huge doesn't mean that they weren't birdlike.  To
paraphrase Yoda: Size matters not; judge them not by their size.

>>      Why do you keep saying that T.rex young were "probably" feathered?  
>> Infant feathers were offered as a purely speculative possible solution to 
>> temperature control problems for young dinosaurs. 
> 
>Because, as we understand dinosaur systematics at this moment in time 
>TYRANNOSAURS ARE CLOSER TO BIRDS THAN ARE COMPSOGNATHIDS.  Period.  
>Tyrannosaurs fall with in the clade Coelurosauria (Compsognathus + Corvis), 
>and so, therefore had the potential to be feathered.

To clarify a point here: Coelurosauria is a stem-based group (Birds and all
taxa sharing a more recent common ancestor with birds than with Allosaurus).

>Just because there arer skin impressions for roughly five groups of large
>dinosaurs (Carnotaurids, Tyrannosaurids, some sort of Sauropods, Ceratopids
>and Hadrosaurs) that have scaly skin, and NO skin impressions of their young
>doesn't mean that they weren't insulated.

Furthermore, MOST of the skin impressions on these forms are known only from
a few patches of the body.  Carnotaurus and hadrosaurids are known with
fairly complete impressions, but tyrannosaurids, ceratopsids, and the
diplodocid are known only from patches.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661

"There are some who call me...  Tim."
-- Tim the Enchanter, "Monty Python and the Holy Grail"
---------- subtitle --[Monty Python ik den Holy Grailen]

"Tim?!?  They called me TIM?!?!"
-- Tom the Paleontologist, on seeing "The Ultimate Guide to T. rex" :-)