|
> I found an interesting site that shows fairly
high > quality photos of Mike Triebold's giant
caenagnathid > at: > >
http://www.trieboldpaleontology.com/casts/oviraptor.htm > > Worth looking at. Indeed... Very short tail (shorter than the legs it seems)
with something like 30 vertebrae... unless the chevronless end of the tail
is a *Nomingia*-style pygostyle (impossible to see).<< No pygostyle, I talked to Mike T. about it. For the
record I was the first to draw not only a Chirostenotes skeleton (1988), but
also the first to draw an Oviraptorid with a short tail! Now this specimen
shows it, and the new oviraptorids at the AMNH. It’s nice to be right
(sometimes, that is). Olshevsky,
G., 1988, A Caenagnathid Specimen from Alberta: Archosaurian Articulations, v. 1,
n. 5, p. 33-36. On the subject of Spinosaurids >>Michael Habib There are only a few prey items that Orcas take that
are their size are larger, these being a few species of
baleen whale. Even
sharks and seals can be swallowed whole.
When attacking a whale, an Orca can indeed tear and rip,
but my understanding is that this ability to tear with
conical teeth pivots on aquatic movement: the Orcas can bite
and then move their bodies in any given direction. Since the neck vertebrae in dolphins (Orcas included) are
short and mostly immobile, the entire body is moved as a unit,
and this produces a mechanical advantage which
tears. This can be a lever-like motion, or a rolling motion. I doubt that a spinosaur (as a terrestrial predator) could use
the same method, especially a roll. Crocs also have conical teeth, and they spin/roll to
tear as well (the infamous "death roll").<< True Orca’s have short necks and use their hole
body, as does crocs. But that is due to their overall shape. Spinosaurids could
have used there necks to shake, like a dog does. Obviously theropods wouldn’t
roll. Another thing people need to remember is that fish eating animals have
interlocking teeth (crocs, pterosaurs, tanyostrophids, etc) and they are not
closely spaced as in spinosaurids. Spinosaurids upper teeth overhang the lower
jaw (typical for theropods) and are much more closely spaced. The premaxilla is
very solid and I can’t see any problem with them attacking large animals. Look
at Baryonyx, not only is there fish scales in its stomach (which just about everyone
seems to hook on) but it also had Iguanodon bones. We don’t know what a
complete skull of a spinosaurid is like so we don’t know if it was lightly or
heavily built (except for Irratator, which seems to be a bit different from the
‘normal’ spinosaurids). Tracy L. Ford P. O. Box 1171 Poway Ca
92074 |