Definitions

Postsegmental plate or lobe bearing anus. [Brusca and Brusca, 2002]
(Taxon-specific: Order Leptostraca) Telson.
(syn. anal segment) [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) Last (fifth) segment of abdomen; bears anus dorsally and pair of caudal rami posteriorly. Occasionally termed telson. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) The posterior somite and abdominal somite onto which the anus opens. The anal somite bears a paired appendage called the caudal rami. The anal somite is considered the first abdominal somite, despite its posterior position, because it is the first abdominal somite to appear during post-embryonic development. [Ferrari and Dahms, in press]
(Taxon-specific: Subclass Mystacocarida) Telson. [Stachowitsch, 1992]