Trilobites Proetus & Ceratarges BIRUG 27102

BIRUG 27102 contains two trilobites – *Proetus steininger* (enrolled) and *Ceratarges gurich* (ornamented). The specimen represents part of the Devonian marine fauna of Morocco. Beginning in the Silurian, trilobites became vulnerable to predation by fish and many genera began to exhibit defensive structures, e.g. spines, to prevent attack. Here, *Ceratarges* shows this kind of ornamentation; *Proetus* is adapted to a different defensive strategy – enrollment (curling up), which it partially demonstrates here. Both individuals here were likely benthic (living on the sea-floor) as the eyes position and morphology suggest a largely dorsolateral field of vision. In free-swimming trilobites the field of vision is usually sufficiently broad to allow some ventral vision, alongside dorsolateral. This specimen was digitised using an Artec Spider 3D scanner by Andrew Jones.