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re:babies and ecology (Bakker)
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
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!
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...
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