re:babies and ecology (Bakker)

["Scott Hartman" <scott_hartman@hotmail.com>]

It occured to me that an inordinate amount of my posts (historically) have 
been to clear up Bob's opinion on something.  I've had the privaledge of 
working with many other talented researchers, and yet somehow...anyway, you 
can draw your own conclusions there.

    As for his baby ecology stuff.  He is attempting to erect a new genus 
of allosaur, which he dubs "Wyomingraptor."  He has been using this name for 
some time, but recently has found a specimen he thinks is different enough 
from the type(s) to warrant generic distinction.  If this order of events 
seems anachronistic to you...anyway, the biggest problem here is that the 
name as-of-yet has no published validity, but his common use of a name with 
the suffix -raptor in it often confuses people into thinking he is referring 
to a dromaeosaur.
    The "stegosaur attack" allosaur pubic boot that was found at Nail 
quarry is almost certainly the result of a blood born pathology, not an 
impact fracture.  The pathology that fused two caudal dorsals together may 
be related (Rothchild didn't think so), and it was certainly caused by a 
blood born pathology.  It preserves the gross shape of soft tissue below it, 
and looks very similar to the pathology Chris Brochu has reported on two of 
Sue's caudal vertebrae.  However, whereas the Sue pathology is almost 
certainly an imprint of the underlying musculature, I would suggest that 
it's equally plausible that the Nail specimen may reflect the shape of the 
kidneys rather than trunk musculature.
    As for the evidence for baby feeding itself?  Equivicable.  The 
parallel grooves on "prey" material does suggest wear-by-teeth rather than 
depositional abrasion.  On the other hand, the "baby" bite marks are 
distinguised by the proximity of the grooves only...which could also be due 
to an adult allosaur raking it's teeth across a bone at an oblique angle.
    There are only allosaur teeth found at the site.  The large number of 
chewed bones and very heterogenic taxanomic makeup of the "chewies" does 
suggest that predators were responsible for concentrating the bones in the 
quarry.  The fact that only allosaur teeth are found, and that there are 
teeth from very imature allosaur specimens does suggest that allosaurs were 
excluding other predators from the food concentration, possibly to the 
benefit of their young.  Finally, allosaur forelimb functional anatomy is 
consistent with modification to reduce stress during mechanical laoding for 
extended periods, i.e. they could have been improving their ability to carry 
food to their young, although there may be other more important reasons for 
these features.

A WARNING TO JURASSIC TEETH PEOPLE

     I have run into a number of people who are researching possible 
maniraptoran teeth from the morrison.  Good.  But the denticles of alosaur 
teeth scale allometrically, resulting in an uncanny resembalance of juvenile 
teeth to the those of troodonts.  At the Wyoming Dinosaur Center in 
Thermopolis, for exapmle, they had identified many juvy allo teeth as 
possible troodonts.  Beware!

Finally

    Bob Bakker is no longer associated with the Tate Museum.  The 
collections from Como Bluff are now housed at Glen Rock, Wyoming, which is 
approx. 25 miles east of Casper.  But the Tate still has some interesting 
stuff...more on that in mid-October.

Sorry about the long email...

Scott
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