Gephyrea is a now-dismantled class of marine

worm Worms are many different distantly related bilateria, bilateral animals that typically have a long cylindrical tube-like body, no limb (anatomy), limbs, and usually no eyes. Worms vary in size from microscopic to over in length for marine ...

s, containing the three modern taxa

Echiura The Echiura, or spoon worms, are a small group of ocean, marine animals. Once treated as a separate phylum, they are now considered to belong to Annelida. Annelids typically have their bodies divided into Segmentation (biology), segments, but e ...

Sipuncula The Sipuncula or Sipunculida (common names sipunculid worms or peanut worms) is a class containing about 162 species of marine annelid worms, that have secondarily lost their segmentation. Sipuncula was once considered a phylum of unsegmented ...

, and

Priapulida Priapulida (priapulid worms, from Gr. πριάπος, ''priāpos'' ' Priapus' + Lat. ''-ul-'', diminutive), sometimes referred to as penis worms, is a phylum of unsegmented marine worms. The name of the phylum relates to the Greek god of fertilit ...

. Also '' Sternaspis'', the first described genus in the family Sternaspidae, was at some point assumed to be related to Echiura and therefore included in the Gephyrea. This class was not

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

. Priapulida are now considered a distinct phylum among

Ecdysozoa Ecdysozoa () is a group of protostome animals, including Arthropoda (insects, chelicerates (including arachnids), crustaceans, and myriapods), Nematoda, and several smaller phylum (biology), phyla. The grouping of these animal phyla into a single ...

, while the other two taxa are classified as

Annelids The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches. The species exist in and have adapted to vario ...

. The word was created by Quatrefages from the Greek ''γέφυρα'' (''géphura'') 'bridge', because these animals seemed intermediate between Annelids and Holothurians.

References

Obsolete animal taxa Protostome classes {{protostome-stub