<i><b>Prognathodon</b></i> was a genus of medium-sized mosasaur, averaging around five meters,
though some individuals might have been twice that size.
This genus was named for having an unusual <b>premaxilla</b>,
which is a bone that is found in the front portion of the upper jaw.
<i>Prognathodon</i> means “projecting jaw teeth”, which refers to
the way the premaxillary teeth stick out from the front of the mouth.
The rest of the mouth was filled with large, ridged jaw teeth and
a nasty set of backwards-projecting pterygoid teeth.
Prognathadons are the bulldogs of the mosasaur lineage,
with relatively short blunt skulls.
However, the proportions of these skulls to the rest of their bodies, is unusual.
While their skulls are massive, and heavily constructed,
the rest of their skeletons are much more delicate.
It often looks like the skulls shouldn't belong to the bodies.
<i><b>Globidens</b></i>, meaning round or globular teeth,
is another mosasaur with a very robust skull.
<i>Globidens</i> are known for
having rounded teeth instead of the mosasaur typical conical spikes.
These mosasaurs were durophagous,
and probably ate only hard shelled invertebrates.
They must have had a lot of them since these animals could reach
over six meters in length.
A modern analog for
this lifestyle is the horn shark, which has plates in the back of its jaws
that are used specifically to crush the hard shells of oysters and clams.