Travel Reference
In-Depth Information
The
Bite
of
a
Mosasaur
Tom Daniel had a great advantage in this controversy, for he is a spe-
cialist in a field known as biomechanics. Biomechanicists are really engi-
neers dressed in zoologist or paleontologist clothing, for it is engineering
principles that they bring to the work bench. This clan has done much work
on the nature of molluscan shell and on how it responds to pressure. Typical
molluscan shell is composed of several distinct layers and is far more than a
simple crystal substance. Tiny crystal of calcium carbonate are interlayered
with tough organic material of the same composition as fingernail. The two
together give far more strength than either one alone. Combined, they form
what is known as a
composite material.
Concrete is another type of composite
material; it is formed of lime, sand, and rock, which, when combined, form a
far stronger substance than any of these materials alone. If you add in rein-
forcing steel rods to the mix, you approach (in design) a molluscan shell.
One great advantage of molluscan shell over concrete is that it is capable of
at least limited bending. Yet in many ways, it also acts as porcelain china
does: It reaches a certain critical point and then shatters. Large cracks run
through the material at high speed, usually producing irregularly shaped sur-
faces. Punching holes in a mollusk's shell or a china plate can be done only
under very bizarre circumstances. Mosasaur tooth pressure does not seem to
be one of them. It seems very unlikely that mosasaurs punched holes in am-
monite shells.
Why dwell on this story of what is now nearly four decades of interpre-
tation about ammonites with holes in their shells as being caused by mosasaurs?
Because paleontology has labored for so long under "stories" rather than sci-
ence. Erie Kauffman long ago found a shell with holes in it. He deduced that
the holes wete made by a marine lizard and then, having come to this con-
clusion, spun out a blow-by-blow tale to support it. Not a single experiment
was ever performed. Tom Daniel, on the other hand, after having been alerted
to this interesting problem by his young daughter, set out to see whether var-
ious hypotheses would stand up to scrutiny. In doing so he employed the sci-
entific method, perhaps the most powerful of all time machines. Tom con-
vinced a grad student named Erica Roux to try actually to
produce
round
holes in nautilus shells (very close approximations of ammonite shells)
