RE: Guts-Eating Spinosaurs

["Tracy L. Ford" <dino.hunter@home.com>]

-----Original Message-----
From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of Fam
Jansma
Sent: Thursday, January 10, 2002 12:10 AM
To: archosaur@reptilis.net
Cc: dinosaur@usc.edu
Subject: Re: Guts-Eating Spinosaurs

Jura wrote:

>Just how delicate is a spinosaur skull? From what I've seen of the skull of
_Baryonyx_, they look to be fairly sturdy. They might not have been made for
whatever it was tyrannosaurs were doing, but I wouldn't really call it:
"delicate."

The skull in at least Suchomimus is very narrow, as is the lower jaw of the
holotype of Spinosaurus aegyptacus. When something is narrow, it is easily
breakable and when you are dealing with struggling fish with it's body
moving all around, the tail could snap the skull. Baryonyx was a relatively
basal creature, so it is logical it is more sturdy in the jaw area, but the
Spinosaurus maroccanus had a very slender jaw. Taken to the extreme in the
7ft skull. Bye the way, does anyone have a picture of this skull that I
could possibly have?<<

Tell crocodile or ghavil that it's narrow jaws are two 'weak' to take down a
wilder beast or large fish. Yes, Spinosaurids skulls are narrow, but
narrowness of the skull doesn't equate to weak. Lots, if not the majority of
theropod skulls are narrow. Monolophosaurus is very narrow, Dilophosaurus is
narrow, etc. Spinosaurids have very thick front jaws and are very strong,
maybe used in a pincer like motion because that is where the thickest,
largest teeth are.

Allosaurus has a 'weak' skull because the skull is not FUSED. All the way
down to the premaxillae and dentary symphysis, spinosaurids are solid there.

I was at Sea World late last year and was watching the Shamu show. The
narrator said that Orca's have conical teeth and they were good for tearing.
If this is true (and should be looked into), then spinosaurids wouldn't have
a problem ripping into an animal.

>Well, maybe _Irritator_, but that was an exceptional skull (and an
imaginative misuse of plaster).

Sure was, with a part of the right maxilla placed on the top of it's head.
Has anybody noticed in the skull of Irritator that the part with the
quadrate and all is placed lower than the rest of the skull? Not just a
little, it makes about an angle 30 degrees. What on earth could be the use
for a skull like that? Flamingos have similair constructed skulls, but I
don't see Irritator hanging it's head up-side-down to catch it's food.<<

I've seen some recent illustrations of the skull (and actually saw the skull
in the middle of last year, but wasn't allowed to photograph it :( ) and the
skull does dip down that way, as does Oviraptors. Why, I don't know.

Tracy L. Ford
P. O. Box 1171
Poway Ca  92074