Tokummia katalepsis


Tokummia katalepsis is a fossil arthropod from the Burgess Shale as found in a quarry in Marble Canyon in Canada. It is an early member of Mandibulata. The fossil is 508 million years old. The animal has maxillipeds, mandibles, ring-shaped body segments, and subdivided basipods. At the front of the animal are mandibles with pincers. This is the oldest fossil with pincers. The speculation is that T. katalepsis grabbed soft bodied prey with the mandibles and them chopped them into pieces so that it could eat. It has more than 50 pairs of legs. The animal is about 10 cm long and has a two piece carapace on its back. It was a bottom feeder, being able to walk on the sea floor, and to occasionally swim. The animal legs have endites which are small spikes on the legs. It has one pair of antennae.
The genus was named after Tokumm Creek which runs through the Marble Canyon where this was found. The species was named after a Greek word for gasping.
The discoverers claim that Tokummia along with Branchiocaris, Canadaspis and Odaraia are very early crustaceans ancestral to the Mandibulata grouping, which includes millipedes, insects and crustaceans.