Gatunek typowy
Leptaena rugosa King,1846, Ashgill, Alleberg (Västergötland), Sweden

Opis

Outline transverse and rounded anteriorly; profile concavoconvex with sharp anterior dorsal geniculation; ornament costellate to unequally parvicostellate; variable but usually well developed concentric rugae; small pseudodeltidium and large chilidium; short dental plates; filed of ventral muscle from subcircular to elongate with bounding ridges usually developed posterolaterally, sometimes curving round anteriorly; lobes of cardinal process elongate, ventrally directed; socket ridges present but usually weak, sometimes with crenulations; dorsal muscle field variably impressed with median ridge often present; transmuscle ridges, diaphragm variably developed in dorsal valve. Two subgenus: L. (Leptaena) and  L. (Septomena) - both similar but second with the distinctive two pairs of dorsal transmuscle ridges. Additional possibly synonyms od this genus described in Roomusoks, 1989 (Astamena, Kurnamena, Oandumena, Schmidtomena, Similoleptaena)

Synonimy
Leptaenella Fredericks, 1918; Leptaenopoma Marek et Havlicek, 1967;  Leptaenulopsis Haupt, 1878;  Oandumena Roomusoks, 1989; Orhoria Havlicek,1990; Turgenostrofia Alekseeva, 1983

Zasięg czasowy

Ordovician (Llanvirn) to Devonian (Pragian, ?Emsian); cosmopolitian.

Literatura