Hurdia

Hurdia victoria is an extinct species of anomalocaridid that lived 505 million years ago during the Cambrian Period. It is part of the ancestral lineage that led to Arthropods and is related to Anomalocaris.
Description
Hurdia was one of the largest organisms in the Cambrian oceans, reaching approximately 20 cm (0.66 feet) in length. Its head bore a pair of spiny claws (great appendages) which shovelled food into its pineapple-ring-like mouth. A hollow, spike-shaped shell protruded from the front of its head. The function of this organ remains mysterious; it cannot have been protective as there was no underlying soft tissue. Lateral lobes ran along the sides of the organisms, from which large gills were suspended.
Ecology
Hurdia was a predator, or possibly a scavenger. Its claws are flimsier than those of Anomalocaris, suggesting that it fed on less robust prey. It displayed a cosmopolitan distribution...