Moroccan Trilobite With Axial Spines
Suborder Illaenina, Superfamily Illaenoidea, Family Styginidae
Hamar Laghdad, Zerg, Morocco
Here is a rarely seen trilobite: A member of the Order Corynexochida,
Family Thysanopeltidae from the Hamar Laghdad Formation Devonian
of Zerg, Morocco. It is Platyscutellum, and is distinguished from
Scutellum by the ribbing of the pygidium. The diagnostic feature
the row of axial spines, not seen in other relatives. This one is
well-displayed upon its matrix platform, and is quite 3-D in aspect.
Notice the may fine holochroal eye facets. Holochrocal have a very
dense packing of small facets with a single corneal layer covering
all lenses. In living arthropods compound eyes are very sensitive
to motion. It is presumed that these were as well, affording a
warning of the approach of would-be predators.
trilobite pictures to enlarge