is one of the more sought after trilobites of the Order Lichida,
Family Odontopleuridae known as Dicranurus monstrosus. This particular
example is quite large at 2.2 inches in length from the dramatic
cephalon to the wonderful pleural spines, and has a "wingspan"
of 2.6 inches at the genal spines. Notice that the librigenae are
tightly attached, a sign of a well-articulated specimen. It is found
in the Lower Devonian Laatchana Formation deposits near Alnif, Morocco.
It is quite prone, and dominates its 2.7 inch by 2.9 inch bed of
matrix. Among its impressive features are the dramatically retorted
occipital spines, looking like ram's horns. In all, there are 18
freestanding spines present, making for an impressive display piece.
To what purpose could this spiny exoskeleton have been evolved?
The answer is simple -- DEFENSE!! Fish had recently evolved
jaws, and in the never ending arms race between predator and prey,
Dicranurus' amswer was a spectacular defensive array of spines.
A substantial amount of prep time goes into a dramatic specimen
such as this.
see: Moroccan Trilobites