Small, phosphatic, fossil teeth, common in rocks from the Cambrian to Triassic (and formerly placed in the category Conodontophora) that belonged to elongated, fish-like animals that were probably chordates (Chordata), possibly vertebrates, and lived as active predators. Two eyes were located in lobe-shaped structures at the anterior end, a notochord ran down the length of the worm-shaped body, there were muscular fins at the posterior end, and the feeding apparatus comprised the only hard parts.