Trilobites
Order Corynexochida, Suborder Illaenina, Superfamily Illaenoidea, Family
Styginidae
Geologic Age: Middle Devonian
Trilobite
is 46 mm long
Hamar Laghdad, Zerg, Morocco
Remarks: Note the axial Spines. Platyscutellum is distinguished from
Scutellum by the ribbing of the pygidium. Note also the holochroal
eyes with many
fine facets. Holochrocal eyes have a very tight hexagonal packing of
small facets with a single corneal
layer covering the many lenses. Many living arthropods have compound
eyes that are very sensitive to motion. It is presumed that these were
as well,
enabling them to quickly spot an approaching predator - trilobites
putatively adapted this trait early in evolution.
Also see: Moroccan Trilobites
