No abstract

All cyclidan species represented by existing material are illustrated photographically. New genera within Cyclidae include Ambocyclus new genus; Carabicyclus new genus; Chernyshevine new genus, Litocyclus new genus; and Tazawacyclus new genus with the following new combinations: A. capidulum (Chernyschev, 1933); A. simulans (Reed, 1908); A. ? minutus (Rogers, 1902); Carabicyclus wrighti (Woodward, 1870); L. bilobatus (Woodward, 1870); L. ? communis (Rogers, 1902); L. jonesianus (Woodward, 1870); L. ? permarginatus (Rogers, 1902); L. torosus (Woodward, 1870); Chernyshevine spinosus (Chernyschev, 1933); T. tazawai (Niko & Ibaraki, 2011); U. harknessi (Woodward, 1870); and U. woodwardi (Reed, 1893). New genera within Americlidae include Brittaniclus and Dziklus with the following new combinations: B. rankini (Woodward, 1868); B. scotti (Woodward, 1894); B. testudo (Peach, 1882); and D. obesus (Schram, Vonk & Hof, 1997). A neotype is herein designated for Halicyne plana. Each family within Cyclida occupies a distinct morphospace. Two families survived the end-Permian mass extinction event. Most cyclidans occupied marine conditions, but some are known from marginal marine and freshwater environments.

a new genus and species of the Cyclida (Crustacea), is reported from the Early Carboniferous (Visean) of Terengganu, eastern Peninsular Malaysia (East Malaya Block). The new genus possesses diagnostic features of both families Cyclidae and Americlidae. Plus, it develops the trifurcate posterior spines: a unique morphology that was not previously known for any cyclidan genera. Based on the possession of an anterior rostrum and optic notches, it is tentatively included in the Americlidae. This represents the first find of the Cyclida from Southeast Asia and the second from the Carboniferous of Asia (eastern Tethys).