Aegirocassis benmoulai Van Roy 2015
Early Ordovician
Lower Fezouata Formation
Eastern flank of Jbel Tigzigzaouine

160mm dorsal flap on 195mm slab. Extremely rare example of one of the largest arthropods of all time.

Arthropod.

Aegirocassis is a genus of anomalocaridid arthropod that is known only from the Early Ordovician of Morocco.  It was almost certainly the largest animal of its time, reaching about 6 1/2 feet long.  Like the largest animal of our time, the blue whale, it has been determined to have been a filter-feeder that descended from predatory ancestors.

Have a look at this amazing 3D model of Aegirocassis courtesy of Google and darwinmuseum.ru. Click on the arrows at the bottom right corner to see it full screen!