Temporal range: Early Ordovician
Van Roy, Daley, & Briggs, 2015
Aegirocassis is an extinct genus of arthropod that belonged to the family Anomalocarididae. It lived during the early Ordovician period, approximately 480 million years ago in what is now Morocco. It is currently only known by a single species Aegirocassis benmoulae.
The A. benmoulae holotype was discovered in March 2015 by a group of palaeontologists in the Fezouata biota, Morocco. It measures 2 m (6 ft) in length and is the earliest example of a filter-feeder to be discovered.