Aegirocassis benmoulai
Arthropod
Early Ordovician (Tremadocian)
Lower Fezouata Formation
Eastern flank of Jbel Tigzigzaouine, facing Oued Ezegzaou, Morocco

Incredible 200mm (almost 8 inches!) anomalocaridid appendage on 400mm block of matrix. Biggest anomalocaridid appendage we have ever had or even seen. A real monster! Extremely rare example of one of the largest arthropods of all time.

Arthropod.  Anomalocarid.

Anomalocaridids were once thought to have died out by the end of the Cambrian, but a new one was described from the Early Devonian of Germany (Hunsruck Shale) in 2009.

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!