Two Ordovician Gastropods and a Trilobite (Onnia) Head - Morocco
This is a pair of interesting Ordovician age gastropod fossils and a trilobite head (Onnia), collected from a location near Hmar Laghdad, Morocco. These gastropods must be mechanically prepared from the hard limestone they are found in.
Gastropods, which are more commonly referred to as snails, have been around since the Late Cambrian period. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. There are 611 known families of gastropods, of which 202 families are extinct and appear only in the fossil record.
Trilobites were a very diverse group of extinct marine arthropods. They first appeared in the fossil record in the Early Cambrian (521 million years ago) and went extinct during the Permian mass extinction (250 million years ago). They were one of the most successful of the early animals on our planet with over 25k described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left a excellent fossil record.