Calymene Trilobite In Nodule From Morocco
Upper Ordovician Period- C. 485 Million Years Ago
Order to which the fossil belongs: Phacopida
Name of which the family belongs: Calymenidae
Informal name of the fossil: Trilobite
Trilobites of this genus have pleural tips turned down steeply and a convex external skeleton with their tail shield being smaller than the head. As this trilobite was a sluggish swimmer it would most likely have walked on the sea bed. This Calymene trilobite nodule contains the positive and negative of the fossil from which it was encapsulated by.
Trilobites are a fossil group of extinct marine arachnomorph arthropods that form the class Trilobite, one of the earliest known groups of arthropods. The name originates from their division into three longitudinal lobes, consisting of a raised central lobe also known as the axis, with two slightly flatter pleural lobes either side. Trilobites also have a head shield known as the cephalon, and on the axial region of the head shield (glabella) they were cheeks either side and well-developed eyes. The thorax consists of up to thirty segments, each would have had a limb but these are rarely preserved. A trilobite would have probably roll up their external skeletons to protect themselves in defence.
Good condition with nice definition.
Trilobite: 23mm x 36mm length
Nodule: 40mm x 42mm approx