Article: Anomalocaris, the largest known Cambrian arthropod

Anomalocaris canadensis Whiteaves, 1892, from the Middle Cambrian of British Columbia, is reinterpreted as an ambulatory arthropod appendage. Three further species from British Columbia, A.I whiteavesi, A. gigantea, and A. cranbrookensis are synonymized with the type. A. pennsyhanica from the Lower Cambrian of Pennsylvania is retained, but the affinities of some specimens remain equivocal and these are designated A.? cf. pennsyhanica. A.? kokomoensis and A.? emmonsi are removed from the genus. An additional appendage originally assigned to Sidneyia inexpectans Walcott, 1911a is redescribed and referred to as 'appendage F'; it may also belong to Anomalocaris and probably functioned in catching prey. The appendage-bearing arthropod is envisaged as multi-pedal with a dorso-ventrally flattened carapace extending laterally over the limb bases; it probably reached a length in excess of 1 m.