Barrandeops cf. granulops from Hamar Laghdad, Morocco
Lower Devonian, Emsian Stage
400 million years
These red trilobites are restricted to Hamar Laghdad. The red color is explained by silicification of the exoskeleton with a combined enrichment in iron. The red trilobites come in varying inensities of red, sometimes bicolored with a grey of a blueish to greenish tint. This might be explained by partial silicification, while other parts remain calcitic, a feature original researched in a red Phacopid with greenish eyes (the blue-green color is induced by elevated iron, manganese contents)
The color of this specimen changes more into a violet tint, the matrix is greyish. This shows how variable the color of this deposit is, depending on the chemistry.