trilobite is a member of the Order Phacopida, Family Acastidae from
the Devonian deposits of Foum Ziguid, Morocco known commercially
as the Short Fork Trident Comura. The Chatterton and Brett had erected
the genus Parabolops, with the long-forked trident being Parabolops
neptunis and the short-forked Parabolops hammi (see my other examples
for a fine long-forked example). Some think the differences may
be the result of sexual dimorphism. Radical differences between
the sexes are common in Arthropods (see some of the scarab beetles,
for example). However, there are over a half dozen known variants,
so unless trilobites had a panoply of sexes the theory does not
hold up to scrutiny. Whatever you call it, this is a spectacular
example. ALL spines have been prerepared freestanding on the cephalon
as well as those on the axial, and pleural lobes, as well as the
pygidial spines making for a dramatic display with OVER EIGHTY freestanding
spines. The diagnostic short trident has been prepared freestanding
as well, making for a dramatic piece unlikely to ever need upgrading.
This one took a great deal of effort to prepare all the pleural
spines free of matrix. This specimen is truly stunning when viewed
from any aspect, and is destined to become the cornerstone of any
collection, public or private. (I apologize for the less-than-esthetic
photography while still in the shipping container, but discretion
was the better part of valor with all the spines).
Palaeontograhica Canadiana, No 25, 2006, pp 33-36.