Anomura (sometimes Anomala) is a group of decapod crustaceans, including hermit crabs and others.

[3] The infraorder Anomura belongs to the group Reptantia, which consists of the walking/crawling decapods (lobsters and crabs).

There is wide acceptance from morphological and molecular data that Anomura and Brachyura ("true" crabs) are sister taxa, together making up the clade Meiura.

[4] Anomura likely diverged from Brachyura in the Late Triassic period, with the earliest discovered Anomuran fossil Platykotta akaina dating from the Norian–Rhaetian aged Ghalilah Formation of the United Arab Emirates.

[1] The cladogram below shows Anomura's placement within the larger order Decapoda, from analysis by Wolfe et al.