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Re: Dinosaur Questions



 From: sgivner@llwnet.ll.pbs.org (Sari Givner)
 > 
 > Here are some questions from a second grade class that has been studying
 > dinosaurs very seriously:
 > 
 > Was the spinosaurus's sail used for protection or battles?
 > When the sail was straight, what was it doing?

I doubt it was for protection or battles per se.
I am not entirely sure of the details of the vertebral spines
in this (relatively poorly known) genus.  The details of the
structure will ultimately tell much about the use.

In my opinion there are two possible uses:
        intimidation display (make it look "fierce")
        thermal regulation   (keep it cool)

I personally favor the first, but it is also possible that *both*
functions applied.
 > 
 > Did the bactrosurus have a sail on its back?

Here again, I am not entorely sure, but my impression is that
it had more of a "hump", like on an American Bison, containing
muscles.
 > 
 > What were the insects of late Jurassic period?

Mostly groups similar to modern insects, but lacking some modern
specialized forms like bees and ants.  I think there were a few
addtional groups that are now extinct, but not very many.
 > 
 > Could Deinonychus swim?

It is very likely it could, that is there is no known reason
why it could not.

 > Was Deinonychus warm-blooded?
 >
This question is a little ambiguous as it stands, but assuming
the most common meainingof "warm-blooded", as equivalent to
"endothermic", the answer is we don't know.  There is some evidence
that suggests it was, and some indications that suggest it was not.

My estimate is that an highly derived theropod such as Deinonychus,
and one so close to the origin of birds, probably *was* endothermic,
and perhaps homeothermic as well.

 > Did triceratops use its mouth the tear down trees?

This has been suggested.  I find it unlikely, as there is little
food value in wood.  (Of course in the dry season, when there is
little food at ground level, tearing down trees to get to leaves
that were out of reach is a possibilty - living elephants do this).
 > 
 > Was dimetrodon's sail used to attract mates or to appear fierce?

I think these are both likely (and they are certainly not mutually
exclusive - they are both forms of display, and a combination
of them could be involved in the evolution of the particular
display mode).

Another widely held theory is that the sail was for thermal
regulation.  That is 
 > 
 > Was pterodactylus an omnivore?

I doubt it.  Its teeth look more like an insectivore to me.
I rather suspect it had a life style similar to modern swifts
and swallows, darting after insects over lakes and swamps.

[Note, Pterodactylus is, properly speaking, the name for a
particular group of pterosaurs (flying reptiles), a group
characterized by a relatively small size, sharp teeth, and
a very short tail].

 > Did pterodactylus have a pouch to store food??

On the basis of this question, I suspect you are really thinking
about the much larger Pteranodon.  This was a toothless pterosaur
with a large beak, and a very large crest on its head.

It has been suggested that this genus had a pouch like a pelican,
but I have seen this questioned.

Either way, however, it was almost certainly a fish-eater that
spent most of its time flying out over the open sea, much like
the similar-sized albatross of modern oceans.

The genus Pterodactylus almost certainly did NOT have a pouch,
and I doubt it was a fish-eater.
 > 
 > Was tyrannosaurus rex a scavenger?

First, this cannot be answered with total certainty.

Second, it depends on what you mean by "scavenger".

If you mean "did T. rex ever eat already dead meat", the
answer is almost certainly, yes it did, as ALL large carnivores
do so.  (The lion will eat anything it can get, dead or alive).

If you mean "did it subsist primarily on carrion like a vulture",
then the answer is very likley no!  With its sharp teeth, large
size, cursorial (fast running) adaptations, extremely strong
front legs, and so on, it simply does not fit the profile of
a primary scavenger.

[Note, I know of NO large living scavengers that do not fly,
since the spotted hyena hunts as much as, or even more then,
the lion - this leaves only the vultures and condors as large
scavengers].
 > 
 > Did parasaurolophus really have 2,000 teeth?

Yes.


P.S. the names of genera are supposed to be capitalized always.
[That is Parasaurolophus, Bactrosaurus, Triceratops, and so on].
 

swf@elsegundoca.attgis.com              sarima@netcom.com

The peace of God be with you.