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?

Well, first of all, alvarezsaurids may not be avian (possibly 
ornithomimoid). Secondly, I wouldn't call it tiny (size probably somewhat 
larger than Velociraptor). Many mammalian scratch-diggers are smaller than 
that.

The morphology of the forelimb does suggest a kind of digging function. In 
particular the length of the olecranon (inlever of the extensor muscles of 
the forearm) to the length of the ulna distal to the humeral cotyla is 
close to the value for mammalian scratch-diggers such as aardvark, 
pangolins, amadillos, etc.
However, I do have a problem with the discrepancy in size between the fore- 
and hindlimb. How do you imagine Patagonykus (or Mononykus) do have done 
the digging.

Gerrit