Aegirocassis - a 480m-year-old marine animal

This extinct marine animal lived 480 million years ago during the early Ordovician - an ancient geological period.

An aegirocassis fossil was discovered in the Fezouata formation in Morocco, along with other animals typical of this period.

The aegirocassis’ closest relative is the famous predator, anomalocaris, which had a round mouth and strange tentacle-like limbs.

The mouth of aegirocassis was capable of a dramatic transformation, forming a strange mesh densely covered with hairs. Scientists think this made the animal the oldest large filter feeder, hundreds of millions of years before whales and large sharks, which catch their prey by filtering it from vast quantities of seawater.

Aegirocassis inherited Its large stalk eyes and flat, segmented body from its Cambrian ancestors. The excellent preservation of the fossil allowed scientists to determine that each body segment had both a ventral and a dorsal flaps - under its belly and on its back. The upper flap helped aegirocassis to breathe, and the lower flaps enabled it to swim. Scientists think the limbs of Anomalocaris were probably arranged in the same way.

3D model by E. Machnev, texturing by A. Akhtamzyan.