Re: Horner on NBC Nightly News (T. rex hunting evidence)

["Demetrios M. Vital" <vita0015@umn.edu>]

On 18 Jul 2001, christopher robert noto wrote:
> Triceratops and hadrosaur bones with healed bites from a T rex.

Triceratops horridus and Edmontosaurus annectens.

> How can
> we be sure that a T rex caused these wounds short of having the tooth
> still lodged in place?

I'm not an authority here, but T. rex teeth are pretty distinguished.  No
other extrememly large theropods hunted where T. rex did, and most other
theropods have a different tooth structure.  T. rex teeth are very round in
cross section, and are more like bananas or railroad spikes than blades,
which is what other theropod teeth resemble closely.

Furthermore, tyrannosaurid incisors have a distinct D-shaped cross section
that is unique among theropods.

Tooth marks are distinguishable marks on bones.  One way, however, to ID
the tooth which was used on a Triceratops sacrum is to take a cast of the
impression, pull the cast out, and compare it to horns and teeth, etc.,
which could leave those marks.  In the case of the Triceratops sacrum, the
tooth was identical to T. rex.

> There is _nothing_ else, not even a Torvosaurus or
> something that could have possibly fed on these animals?

Nothing with thick, large, round teeth that would be eating Triceratops.

> or am I getting ahead of myself before a paper is
> published on this?

You might be, but there are already several paper out on the issue, and the
E. annectens specimen has been known for a long time.  See, for example,
the Scientific American Book of Dinosaurs, with its article on
tyrannosaurid teeth.

Hope this helps,

Demetrios Vital