Re: alvarezsaurid arms

[Gerrit Hanenburg <G.Hanenburg@inter.NL.net>]

> > I'm going to make a picture of Patagonykus, ripping open a termites nest, 
> > but then it struck my mind that the walls of there nests are extremely 
> > hard; could this tiny avian really rip open these hard walls just like that?

I just read the paper on Sinosauropteryx (Currie & Chen, 2001). There are 
some interesting parallels here: "Both phalanx I-1 and the ungual that it 
supports are massive, each being as long as the radius and thicker (shaft 
diameter of 3.5 mm in NIGP 127586 and 6.5 mm in NIGP 127587) than the 
shafts and the distal ends of either the radius or the ulna. The great size 
of the first phalanx of the first digit is a character that also seems to 
have been present in Compsognathus. The only other theropods with similar 
size relationships between the forearm and the first digit are 
alvarezsaurids like Mononykus (Perle et al. 1994). There are too many 
anatomical differences between compsognathids and alvarezsaurids to suggest 
close relationship, and the similarities probably represent convergences."
Also they speak of a "powerful olecranon process" (almost 20% the total 
length of the ulna). However, one of these specimens was found with 
symmetrodont jaws and skeletal elements in the stomach region.
So, would anyone suggest digging for symmetrodonts?

Currie, P.J. & Chen, P. (2001). Anatomy of Sinosauropteryx prima from 
Liaoning, northeastern China. Canadian Journal of Earth Sciences. p.1705-1727.

Gerrit