Brachyampyx Ampyx is an Ordovician-Silurian genus of Asaphid trilobites of the family Raphiophoridae.

[2] Species of Ampyx grew to an average length of 1.5 inches (3.8 cm).

Fossils of the trilobite Ampyx priscus, dating back about 480 million years ago, have been recently described as clustered in lines along the ocean floor.

The animals were all mature adults, and were all facing the same direction as though they had formed a conga line or a peloton.

The findings suggest animal collective behaviour has very early evolutionary origins.