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Re: Question about Archaeopteryx's (non) reversed hallux



David Marjanovic wrote:

No theropods except Scansoriopterygidae and Ornithothoraces have reversed halluces, in spite of earlier mistaken reconstructions. *Confuciusornis* has medially directed ones -- the intermediate condition.

Can we be sure that scansoriopterygids (_Epidendrosaurus_ and _Scansoriopteryx_) have a reversed hallux? While it is true that metatarsal I articulates fairly distally on the pes, such that its trochlea is around the same level as the trochleae of digits II-IV, the morphological correlates of a *reversed* hallux have yet to be identified in the _Epidendrosaurus_ or _Scansoriopteryx_ specimens. (Refer to Scott's post to see what I mean.) BTW, I'm not discounting the possibility that scansoriopterygids might have a reversed hallux. What I'm saying is that this determination will have to await a thorough examination of the halluces of these specimens.


As for Ornithothoraces, I don't believe there is any evidence that a reversed hallux is primitive for this group. It is more likely that enantiornitheans and euornitheans (including Neornithes) evolved a reversed hallux independently.

But to reiterate another of David's points, reconstructions that show(ed) _Archaeopteryx_ with a reversed hallux are mistaken.

Cheers

Tim