Thamnocephalus Packard 1883

Rogers, D. Christopher, 2006, A genus level revision of the Thamnocephalidae (Crustacea: Branchiopoda: Anostraca), Zootaxa 1260, pp. 1-25 : 8-9

Genus Thamnocephalus Packard 1883

Thamnocephalus Packard 1883 ; Linder 1941; Moore & Young 1964; Belk & Pereira 1982; Cohen 2002

Diagnosis ( Figure 1 A). Penes sub­cylindrical, basal portion with a small, chitinized, digitiform medial projection. Everted penes each with a single large medial spine, two large apical­lateral spines, and one large lateral tubercle bearing a single large spine with several smaller spines. Everted penes with one apolateral, longitudinal row of spines, and one sub­transverse row of spines starting apolaterally, extending transversely across ventral surface, and terminating near base of large medial spine. Everted penes extending to second abdominal segment. Abdominal terminal segments with lateral carinae joining cercopods. Cercopods transverse and, together with abdominal lateral carinae, forming broad ‘paddle­like’ structure. Cephalic appendage present in males; may be elongate and branched or short and simple. “Antenna­like” appendages absent. Female second antennae elongate.

Two subgenera with four species. Dumont and Negrea (2002) erroneously report this genus as endemic to Central America. In reality, the genus is reported from Montana state at the Canada border in USA, south through the northern half of México, and from Venezuela, Aruba, and Argentina.

Figures

FIGURE 1. Representative left penes of thamnocephalid genera and subgenera: A) Thamnocephalus platyurus, ventral view; B) Carinophallus ornata upper image (with penes retracted) left ventrolateral view of genital segments; lower image ventral view of everted pene; C) Dendrocephalus c ervicornis, ventral view; D) Dendrocephalus (Dendrocephalinus) acacioidea, ventral view; E) Phallocryptus sublettei, ventral view; F) Gurneya mirus, ventral view; G) Branchinella wellardi, ventral view; H) Branchinella budjiti, ventral view; I) Branchinella (Branchinellites) ondonoguae.