Description:
This is a very fine, 3-D prone example of a trilobite previously
assigned to the genus Phacops, with few in such a pristine, undistorted
shape. Phacops is particularly well known for its Schizochroal eyes.
This type of trilobite eye typically has fewer lenses, but they
are much larger, with each lens separated from its neighbors and
having an individual cornea. The details to this specimen are readily
evident in the photos. The Moscow Formation is the youngest formation
in the Hamilton Group, and is known for the largest known examples
of several trilobite taxa. While this may not be the largest of
its type, there can be no dispute as to the quality of the preservation
of this specimen.
The
genus name for this trilobite is variously called Phacops or Eldredgeops,
with the latter named after Niles Eldredge, whose study of Phacops
trilobites from Ohio led him to hypothesize that modifications to
the arrangement of the trilobite’s eye lenses proceeded in
rapid change followed by stasis over millions of years during the
Devonian. Eldredge's interpretation of the Phacops fossil record
was that the aftermaths of the lens changes, but not the rapidly
occurring evolutionary process, were fossilized. This and other
data led Gould and Eldridge to publish the initial paper explaining
punctuated equilibrium in 1971.
|