|
See Maniraptora - avian-style semi-lunate carpus allows for greater range of motion in the wrist. Presumably this evolved hand-in-hand (pun intended) with pennaceous wing feathers - having them and being unable to fold up the forelimb in the avian fashion would expose the feathers to damage. This is getting into speculative territory, but if pennate wing feathers evolved primarily for display and/or for purposes of brooding, then there is an imperative to protect them & hence evolve the semilunate carpus. T.Y. From: dinosaur-l-request@usc.edu <dinosaur-l-request@usc.edu> on behalf of Tim Williams <tijawi@gmail.com>
Sent: Monday, March 27, 2017 2:17 AM To: dinosaur-l@usc.edu Subject: Re: [dinosaur] Dinosauria reclassification joins Ornithischia and Theropoda in Ornithoscelida Ruben Safir <ruben@mrbrklyn.com> wrote:
> in essence there is a cost to the forelimbs not being modified If by "modified" you mean shortened - then it's been argued that there is a cost to bipeds (especially cursorial bipeds) in retaining long forelimbs (e.g., Carrier et al., 2001; Persons & Currie, 2017). This cost can be mitigated by evolving ways to fold/flex the forelimbs close(r) to the body. |