Geoscience Reference
In-Depth Information
agedtogetasnackbybitingachunkoffleshandboneoutofhistail.Thehadrosaur
escaped with onlyawound,andhelived happily ever after until dyingofsome oth-
er cause and getting fossilized. For the rest of his life, though, he ate plants near the
ground, which were more likely to include grit that scratched his teeth. Although
this scenario was imagined, the trace fossil evidence for all such behaviors is real.
This realization that bodies were substrates for dinosaur behaviors enables us
to discern much more than just looking at the rocks surrounding and entombing di-
nosaur bodies. For example, how can one tell whether or not dinosaur toothmarks
on a dinosaur bone were punched into or scraped against it while the prey was still
alive, dying, or dead? How does one go about identifying dinosaurs that left tooth-
marks,especially iftheywerenotkindenoughtoleave acalling cardintheformof
a dislodged tooth?
Dinosaur toothmarks are not just recorded in the bones of other dinosaurs but
also in bones of vertebrates that lived at the same times and places as dinosaurs.
Even dinosaur teeth, which in some places might be the only body fossils reflecting
a dinosaur presence in Mesozoic rocks, can host trace fossils, too. Some of these
tracesareextremelysubtle,suchasthemicroscopicmarksimpartedwhendinosaurs
chewed plants with grit on their leaves or with mineralized parts. Other traces are
more overt, such as broken teeth of carnivorous theropods which must have bitten
off more than they could chew.
Bylookingatthesebodypartsandtheirtracefossils,manyquestionsaboutdi-
nosaurs become more answerable. For instance, how did they relate to one another,
especially if they became upset with another of their own species? Were predatory
dinosaurs picky eaters, only going after one species of prey, or were they more op-
portunistic,eatingwhateverappealed(andwasavailable) atthetime?Didtheynor-
mally eat big adults, or did they primarily seek out juveniles, or the old and weak?
How did they eat: daintily, with a furtive nibble here and there, or with the glut-
tonous bad manners of a Renaissance-festival banquet? Did some dinosaurs prey at
all, or did they live their lives mostly as oversized vultures, relying on the kills of
