Glypheidea is an infraorder of lobster-like decapod crustaceans, comprising a number of fossil forms and the two extant (living) genera Neoglyphea and Laurentaeglyphea: The infraorder was thought to be extinct until a living species, Neoglyphea inopinata, was discovered in 1975. They are now considered "living fossils", with over 256 fossil species discovered, and just two extant species.

Phylogeny

Glypheidea belongs to the clade Reptantia within the order Decapoda, although its exact placement within Reptantia is difficult to determine. Some phylogenetic studies consider Glypheidea to be most closely related to the infraorder Astacidea, which consists of the lobsters and crayfish, whereas other studies instead consider Glypheidea to be more closely related to the infraorder Polychelida, a group of deep-sea blind lobsters.

Taxonomy