Rare Heliopeltis Moroccan Trilobite

Description: A member of the Order Corynexochida, Family Styginidae from the Early/Middle Devonian deposits of Jebel Issoumour, 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. I have included a few in-preparation photos so you can see the process of freeing these dramatic spines in the process.

Also see this Kolihapeltis rabatensis.

Reference: Papers in Paleontology, 20215, pp1-33.