Bicolor Barrandeops gragulops Moroccan Trilobite

Description: This Phacopid trilobite comes from a new deposit in a location known as Hmar Lakhdad in Morocco. Hmar lakhdad means “red cheeks” in Arabic, an allusion to the rich wine red color preserved in the specimens from this location, a consequence of high levels of iron in the silicified exoskeleton. Some Phacopids have been found with a red exoskeleton and green eyes, a consequence of differential degrees of silicification of the lenses and its impact on iron and possibly manganese contained therein. While this example does not possess the green eyes, it is the same species as the one described in the literature. What is unusual about this one is that while the cephalon and pygidium are wine red, the thorax is a dark brownish gray. The specimen must have died in a vertical orientation and weathering in situ caused the unusual differential coloration. This is the first such specimen from this new site I have been able to secure.

Reference: Acta Paleontologica Pol, 54 (1) 2009, pp 117-123.