Onnia superba

There are two, Onnia superba, on this plate. They are from the Upper Ordovician- Ktaoua Formation, Erfoud, Morocco.

The bodies of both of the fossils have their 'tails' tucked under, but are visible. The fossils are well-preserved- the perforations on the cephalic shields are clearly visible. The color is natural, it is caused by the deposition of iron on the organic material during fossilization.

The trilobites with the matrix measure 2.55 by 2.55 by 1.0 inches.