Re: [dinosaur] Oksoko, new oviraptorid from Late Cretaceous Nemegt Formation of Mongolia (free pdf)

[Tim Williams <tijawi@gmail.com>]

 Ethan Schoales <ethan.schoales@gmail.com> wrote:

> What about forelimb use in non-pennaraptoran theropods?

Good question.  I side with those who regard theropod forelimbs as
being not all that important in predation, as a general rule.  This is
uncontroversial for all herbivorous theropods (like oviraptorids), of
course, and for exceptionally short-armed predators like
tyrannosaurines and carnotaurines.  But in my view it also applies to
theropods with relatively long and/or robust robust forelimbs, such as
dilophosaurids, megalosauroids, and allosauroids.  The forelimbs had
limited cranial/anterior reach - they couldn't even reach the mouth,
and could only seize prey that was positioned directly under the body.
On top of that, an individual manus had no prehensile abilities, and
could only grasp objects in a two-handed fashion.

We know of a _Dilophosaurus_ individual that survived for many months
(possibly years) with a pair of severely damaged forelimbs (Senter &
Juengst 2016; doi:10.1371/journal.pone.0149140).  This tells me that
this particular theropod could survive quite well without forelimbs in
working order.  In fact, I doubt it needed its forelimbs at all to
catch prey.  I suspect this applied to many other relatively
long-armed predatory theropods as well.  So it's no surprise to me
that so many theropods reduced their forelimbs, or co-opted them for
other purposes such as display or locomotion (not mutually exclusive).
It's possible that certain of the larger dromaeosaurids used their
long forelimbs to grasp large(r) prey; but then again, I'm also
partial to the Raptor Prey Restraint (RPR) model (Fowler et al. 2014;
doi.org/10.1371/journal.pone.0028964 ).  But in general, the forelimbs
of predatory theropods played an auxiliary role, perhaps to help
subdue or position large prey seized and held by the jaws - assuming
the predator targeted comparatively large prey at all.

> And what's up with Caudipterygidae vs. Caudipteridae?

Caudipterygidae is the correct name for the family, since it's formed
from the genus _Caudipteryx_ - just as Archaeopterygidae is formed
from _Archaeopteryx_.  But certain workers have erroneously used
Caudipteridae.