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RE: Claw function in Deinonychus



Jaime A. Headden wrote-

<Achillobator's ungual seems to be manual (Senter et al., 2004), as I had
listed as a possibility back in 2000
(http://dml.cmnh.org/2000Oct/msg00476.html). Same with Unenlagia? paynemili's,
by the way. Which makes Makovicky et al.'s claim it was nearly identical to
Neuquenraptor's pedal ungual pretty laughable.>


Didn't Tom Holtz comment about offensive remarks concerning future peers?

Since when is "pretty laughable" offensive? I didn't intend any malice. The unguals are simply not very similar at all, which makes me amused that Makovicky et al would state so plainly otherwise.


Based on what features do you infer these differences? Are these concerning
the unpublished inferrences that have been made offlist, or exact features
backed up by statistical and comparitive data culled from a decent sample of
articulated specimens?

That would be 'exact' features culled from the existing sample of basal paravian unguals. Namely, the large angular flexor tubercle, and the dorsal margin which arches high over the proximodorsal edge (when the articular surface is vertical). The same characters used by Senter et al. (2004) to refer Achillobator's ungual to the manus.


I would strongly suggest actually detailing and cataloguing this data for
statistical studies of the variation and similarities between manual and pedal
unguals in order to properly distinguish these elements, if found isolated.

Sounds interesting, but I don't have the time, interest, or statistics software for it.


For example, segnosaurs from
*Erlikosaurus* to *Beipiaosaurus* (but absent in *Alxasaurus*) also possess
these "manual" features in their pedal unguals, indicating the functional
interpretation of large, recurved, narrow unguals may exhibit similar features
if their functions coincide.

True, but neither Achillobator nor Unenlagia were therizinosaurs, so we can infer they lacked the distinctive pedal morphology of the clade, and instead limit comparisons to other paravians.


Mickey Mortimer