Many other phyla are found there : Porifera ( sponges ) and Priapulida ( burrowing worms which were ambush predators ), Brachiopoda ( these had bivalve-like shells, but fed by means of a lophophore, a fan-like filter which occupied about of half of the internal space ), Chaetognatha ( arrow worms ), Cnidaria, Ctenophora ( comb jellies ), Echinodermata, Hyolitha ( Lophophorata with small conical shells ), Nematomorpha, Phoronida ( horseshoe worms ), and Protista.
