Omnidens amplus, meaning "large all-tooth", is an extinct species of large Cambrian animal known only from a series of large mouth apparatus, originally mistaken as the mouthparts of anomalocaridids.When first named, it was interpreted as a giant priapulid, but is now considered a panarthropod. Its mouth apparatus closely resembles that of the smaller gilled lobopodian Pambdelurion, indicating it is likely to have been a close relative of that species, with which it may be synonymous. With a maximum estimated body length of 1.5 metres (4.9 ft), Omnidens is the largest known free-living Cambrian organism.Omnidens fossils are found in the Maotianshan Shales.