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Re: Palms in



On Sun, 9 Jul 2000, Larry Febo wrote:
> -----Original Message-----
> From: Scott Hartman <scott_hartman@hotmail.com>
> Date: Saturday, July 08, 2000 6:06 AM
> Subject: RE: Palms in
> 
> >I have to agree with Matt (and Serano, well I'm at it) that many, if not
> >most theropods couldn't pronate the palmar side of their manus ventrally.
> >This is taken to an extreme in allosaurs, which seem to have modified the
> >distal end of the ulna and radius in order to reduce mobility around the
> >long axis of the forearm.  Why did they do this?  >     Of course, there is
> yet another "why" here, specifically: Why would an
> >allosaur want to do this?
> 
> (snip)
> 
>   At the time, I was working with Bob Bakker on
> >Nail Quarry out at Como Bluff.  The taphonomy of the quarry suggested that
> >juvenile allosaurs were regularily feeding on large animals (mostly
> >sub-adult sauropods) to the exclusion of crocodillians and non-allosaur
> >theropods.  So he  speculated that the quarry may represent a "lair," or
> >some place were juvenile allosaurs were waiting for an adult to bring home
> >the Apatosaurus bacon.  Naturally this dovetailed nicely with my work.  I
> >balk, however, at commiting myself to this kind of (what, 17th level
> >inference?) behavioral hypothesis without better support.
> 
> It is also suspected now that T. Rex also cared for it`s young in such a
> way. How then did it "bring home the bacon"?....Either many trips, or it
> used it`s mouth,....(perhaps regurgitated food).  I still think a better
> explaination for such  restricted movement in theropods in general is a
> cause of their being secondarily flightless. Once specialized for flight,
> such bone structure would be hard to unmodify for other uses.
 
To expand a bit more on Bakker and Como Bluff - last November I 
attended a talk by Bakker here at the University of Wyoming. Here's
what he said about recent work at Como (and which I posted here):

 ...
 Regarding predators, he said he'd been looking for baby
 teeth for years. Age can be discerned from shed teeth.
 He said he's such teeth. The slide(s) showed these
 such a tooth on the end of a match stick. These were 
 tiny teeth. In fact, he's found 35 of them at this
 site. Basically, it's a nursery. There are remains
 of 30 different animals (species?) here. The bones
 have been nibbled on. The slides showed tiny gnaw marks.
 In fact, the bones show both tiny and large gnaw marks.
 This indicates the parents also chewed on the bones.
 It seems, just like with bullets and a gun, the gnaw
 marks are distinctive.

 The bones at the "nursery" included predator bones. The
 idea is that in a warm, tropical climate, meat rots
 before long, attracting other predators. 

 Also, adult teeth, of the same species as the baby teeth,
 were found at the same site.
 ...
 After the talk I asked if the finds at this "nursery"
 represented one breeding season. He thinks so. There
 are two events where flooding apparently covered the
 site with material. The nibbled on bones do not show
 cracking or other weathering effects, so they 
 apparently were covered up not long after. 

A pertinent question now is what size were these nibbled bones?

I have troubles picturing regurgitation of large bones - ouch -
so my guess would be they were brought back either by "hand"
or mouth.