♪ KU choral chant ♪
♪ subtle, dramatic music ♪
My name is David Burnham. 
I'm in charge of field collections
 of dinosaurs and their 
preparation at 
the University of Kansas. 
I was involved with
 Tyrannosaurus Rex 
almost from 
the very beginning of my career. 
T-Rex has been debated by 
scientists for about 100 years. 
We have physical evidence 
that dinosaurs bones are being 
eaten and we know they've been eaten
 by T-Rex because we can 
see the tooth marks on them. 
On the other hand, we don't know
 if they were eaten when 
they were alive or dead. 
As a scientist, 
we require physical evidence. 
We need proof. 
We had a graduate student, 
Robert DePalma, 
doing his research in South Dakota. 
The Hell Creek Formation, 
where it's very famous 
for dinosaur discoveries. 
He was cleaning fossils up 
and said right away he knew that 
this was abnormal. 
We're looking at two fused tailbones
 to a duck-billed 
dinosaur and the reason the bones
 are fused is because this 
is sick bone growth. 
All this rumply stuff, 
this is bone that was infected. 
We became interested in this 
because fossils tell stories and 
when you get a sick fossil, 
it may tell an interesting story. 
So we cleaned this up 
and we saw a circular cross-section 
right here and 
realized it was a tooth. 
The tooth had broken off 
and infected the animal. 
The animal obviously 
got away because
the bone grew around 
the tooth. 
We had this idea: well if we can identify 
the tooth, we know 
who bit the dinosaur and boy, 
wouldn't it be cool if it was a 
T-Rex because we could finally show
 that, once and for all, 
we have the physical evidence 
that it was a predator. 
We brought it to the hospital 
to get CT scanned and once we 
had the CT scan, we could see 
there was an entire tooth in there. 
This is the tooth crown that was
 extracted out of the 
hadrosaur and you can see 
that it's still has the serrations. 
That's the cutting edge 
and there's one on the front and one 
on the back and those serrations
 are like a steak knife. 
You can count the serrations, 
per millimeter, define their 
shape, and they're like fingerprints,
 they can tell you which 
species of dinosaur this tooth
 belonged to. 
We were able to determine 
that it was a Tyrannosaurus Rex 
based on certain 
bits of morphology 
that are unique to that species. 
This is what a complete
 T-Rex tooth 
would look like 
just for comparison. 
See, just the tip broke off
 from the tail. 
Finding a T-Rex tooth embedded 
in the tail of duck-billed 
dinosaur that got away and escaped
 the attack and we know 
that because the bone 
healed around the tooth, 
settles it, 
settles that debate. 
You've got T-Rex, hands down,
 predator. 
Just like any 11-year old will tell you:
 What did T-Rex eat? 
Anything it wanted. 
(laughs) 
Here at KU, we've got one of
 the best programs
in the world. 
We strive to be best in the field
 and we have been 
for quite a few years. 
 
