Geoscience Reference
In-Depth Information
Despiteausurpingoftyrannosaursbycrocodiliansaschampionbiters,other
T.
rex
toothmarks invoked awe-inspiring scenarios of this dinosaur occasionally say-
ing “Off with their heads!” This gruesome idea came about when Denver Fowler
and several other paleontologists noticed, while looking at
Triceratops
bones from
the Late Cretaceous of Montana, that some of the outer frills of
Triceratops
skulls
had toothmarks on them, which once again matched those of
Tyrannosaurus rex.
The most perplexing aspects of the toothmarks, though, were their specific loca-
tions. Some were along the edges of
Triceratops
head frills, whereas others on the
same skeleton were on the neck vertebrae. The toothmarks on the skull showed no
signs of healing and were from teeth on upper and lower parts of the jaws punc-
turing opposite sides of the frill: no scraping or pulling, just clamping. For feeding,
thesetracesdidnotmakemuchsense,becausetherewasverylittleceratopsianmeat
to be enjoyed on its skull. In contrast, toothmarks on the neck vertebrae were more
puncture and pull, definite traces of where the tyrannosaurs bit into and pulled off
scrumptious hunks of ceratopsian flesh.
To answer this mystery, take another look at a
Triceratops
skeleton, and you
will note that its huge frill covers its neck quite thoroughly and effectively. Hence,
it is intuitively obvious to even the most casual observer that this dinosaur not only
must have been already dead for a tyrannosaur to feed on its neck muscles, but also
must not have had a frill in the way. Accordingly, the easiest way for a tyrannosaur
to access that flesh would have been to remove the frill. For
T. rex
to do this, given
theirjawstrengthandbodymass,allitwouldhaveneededtodowasbitedownonto
the edge of a
Triceratops
frill, tug, and yank the head from the body to expose the
good stuff below. In such a scenario, it also may have used one or both of its feet to
stabilize the
Triceratops
body while pulling.
So these trace fossils tell us that
Tyrannosaurus
ate dead dinosaurs, which is
good to know. But some of us want something more to satisfy our bloodlust. In our
minds,
T. rex
was not a big vulture, however noble vultures might seem to be in
theirownway.Instead,weimagine
T. rex
orothertyrannosaursasapexpredatorsof
