Marella, a small, primitive arthropod, was the most abundant animal of all in the Burgess Shale fauna.
It may have lived in large shoals on the sea bed, and probably fed on tiny particles that it swept up with specialised brush-like structures on its antennae. Marella had two pairs of large spines on the head. The back pair were as long as the rest of the body and may have provided protection against predators.