[1][2] In 1995, Gerhard Scholtz and Stefan Richter of the Freie Universität Berlin carried out a phylogenetic study of the "Reptantia", and concluded that "Palinura" was paraphyletic.

Polychelida is the sister clade to the infraorder Astacidea, which contains the "true" lobsters and crayfish.

The cladogram below shows Polychelida's placement within the larger order Decapoda, from analysis by Wolfe et al., 2019.

The animals grouped into the infraorder Polychelida are united by the presence of at least four pairs of chelae (claws).

[5] The group has a fossil record stretching back to the Upper Triassic,[2] and had its peak diversity in the Mesozoic.