Re: Dino feathers=Ptero fur?

["Nicholas J. Pharris" <pharrinj@PLU.edu>]

On Thu, 8 Feb 1996, Nicholas R. Longrich wrote:

>       Arctometatarsialian has been used about 500 times, but could 
> somebody please define it? And did those cladograms actually put T. rex 
> closer to modern birds than Archaeopteryx, or was I misreading that? 

The Arctometatarsalia are a group of Cretaceous theropods (tyrannosaurs, 
ornithomimids, and troodonts are the best-known representatives), 
characterized by, among other features, a foot constructed with the top 
of metatarsal III hidden behind metatarsals II and IV and tapering to a 
point (see crude attempt at diagram below):
   _ _
  | | |
  | | |
 / / \ \
 |_|_|_|

II III IV

(cranial view of left metatarsus)

To answer your second question:  

Yes, based on foot and braincase features, I believe arctomets (including 
_Tyrannosaurus_) to be more closely related to modern birds than 
_Archaeopteryx_, although Tom and George, just to name a few, disagree.

Nick Pharris
Pacific Lutheran University
Tacoma, WA 98447
(206)535-8204
PharriNJ@PLU.edu

"If you can't convince them, confuse them." -- Harry S Truman