Definitions

In copepods, part of body behind major articulation marking posterior boundary of prosome; in amphipods, last three abdominal somites bearing modified appendages. [Moore and McCormick, 1969]
Limbless abdomen of some copepods. [Brusca and Brusca, 2002]
Part of body behind major articulation (Copepoda); also last 3 abdominal somites bearing modified appendages (Amphipoda). [McLaughlin, 1980]
Posterior division of the abdomen in amphipods; bears appendages (uropods) and telson. [Brusca and Brusca, 2002]
(Taxon-specific: Order Amphipoda) Posterior of two subdivisions (pleosome, urosome) of abdomen (pleon). Consists basically of three somites (urosomites), each bearing pair of appendages (uropods). [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) That part of the adult copepod body posterior to the major body articulation. [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Copepoda) The region of the body posterior to the major articulation, includes the fifth pedigerous somite in podopleans, but not in gymnopleans. [Boxshall and Halsey, 2004]
(Taxon-specific: Class Ostracoda) Posterior division (tagma) of body (prosome, urosome, or cephalosome, metasome, urosome). Corresponds to region of body posterior to main flexure point (or posterior to genital complex in forms without body articulation) and includes both thoracic and abdominal somites. [Stachowitsch, 1992]