Order Corynexochida, Family Styginidae
Time: Middle Devonian
inch): Trilobite is 70 mm long, 65 mm across (with spines). Matrix: 95
mm by 110 mm.
Quadrops Couche, Tazoulait Formation, Jebel Ofaten, Morocco
A member of the Order Corynexochida, Family Styginidae from the
Early/Middle Devonian deposits of Jebel Ofaten, Morocco, this is
a member of the
genus Heliopeltis. The dramatic occipital spines make this one easily
distinguishable from other members of its family. Indeed it appears
to be almost entirely composed of spines, quite a mouthful for any
would-be predator. Once known as Andegavia, these trilobites are
only rarely offered. I have seen less than a literal handful in
15 years, and all are in this contraflexed position. The authors
of the paper that described these unusual trilobites speculate that
they are molts or possibly pulled into this posture postmortem by
muscular contraction. I personally think the latter view more likely.
Notice the many fine eye facets on this specimen. I have included
a couple of inprep photos so you can see what a task it is to free
the many spines from the hard entombing matrix. For a more often
seen but nonetheless dramatic relative see my other posting
see this Kolihapeltis
Papers in Paleontology, 20215, pp1-33.