Geoscience Reference
In-Depth Information
shouldthenbeappliedtodinosaurtoothmarks.Whenpaleontologistslookatabone
with dinosaur toothmarks in it, they most often assume that the bone belonged to
an already-dead animal. Nevertheless, they could also look closely for signs that an
animal may have still been breathing, and possibly adding its traces to that of its
attacker.
More good questions to ask include “Who did it?” which relates to the tooth
anatomyofthedinosaurthatmadethetoothmark,and“Howdidthisdinosaurbite?”
For example, did the dinosaur rake its teeth across the surface of a bone as it was
tugging meat from it? Or did it punch past skin, muscle, and other soft tissues and
go directly into the bone? Did it mostly use teeth from its upper jaw (maxilla), or
did it also use its lower jaw (mandible)? Which teeth were used in the biting: ones
toward the front of the mouth, ones more toward the back, or a combination of the
two? Did the dinosaur bite multiple times in the same general area, inflicting an
overlapping array of toothmarks? And in a related question, did more than one di-
nosaur snack on this delectable treat, adding its toothmarks to a varied collection?
Beforegoingonanyfurtherwithtoothmarks,though,itisprobablyagoodidea
to learn about dinosaur teeth, and with a focus on theropod teeth, because thero-
pods included a large number of dinosaurs that ate other dinosaurs. Like many oth-
er groups of toothed vertebrates, theropods had a wide variety of tooth shapes and
sizes appropriate for their varied uses. Although paleontologists now know that not
all theropods were meat eaters, and some were even toothless, we are also aware
that “meat eating” is too broad a category for toothed dinosaurs to have evolved
“one-shape-fits-all” tooth forms, too.
For example, a few smaller theropods, such as the Late Cretaceous theropods
Velociraptor
and
Saurornitholestes
,hadthin,curved,andbeautifully serratedteeth.
In contrast, larger Late Cretaceous theropods, such as
Daspletosaurus
and
Tyran-
nosaurus
, had thick, stout teeth with only minor serrations. Serrations on theropod
teeth were formed by numerous raised and bladed bumps called
denticles
, which
were evenly spaced along the narrowed edge of a tooth. These functioned just like
