> I found an interesting site that shows fairly high
> quality photos of Mike Triebold's giant caenagnathid
> Worth looking at.
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
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