It belongs to the larger hurdiidae (peytoiid) family, which were the most diverse and long lasting radiodonts.

The members of this subfamily are restricted to the Lower Ordovician-aged Fezouata Formation of Morocco.

These two genera possess large Baleen-like auxiliary spines on their frontal appendages, which suggests a suspension feeding lifestyle for the group.

It also seems that due to the evolution of new predators, like large nautiloid cephalopods, and other arthropod groups like the eurypterids, the radiodonts evolved suspension feeding lifestyles in order to minimize competition for food.

[2][1][3][4] Aegirocassisines are distinguished by their frontal appendages possessing endites that bore long auxiliary spines (the longest of any radiodont).