Genus Liothorax Motschulsky, 1859

Liothorax Motschulsky 1859: 156, Ádám 1994: 14, Dellacasa et al. 2001a: 169 Aphodius (Liothorax); Bedel 1911: 74, Dellacasa 1983: 276

Ataeniomorphus Balthasar 1952: 22, Stebnicka 1990: 897 (as a synonym of Liothorax)

Type species: The type species of Liothorax is Scarabaeus plagiatus Linné, 1767 by subsequent designation (Dellacasa 1983). The type species of Ataeniomorphus is Aphodius isikdagensis Balthasar, 1952 by original designation.

Diagnosis: Small or medium sized species (length 4.0–6.0 mm), convex, cylindrical, elongate, glabrous, shiny or dull. Black or piceous-black, rarely with red or yellow spotted elytra or completely red or yellow elytra; sometimes elytra with alternating yellow and black interstriae; rarely elytra black with lateral margins yellow. Head anteriomedially moderately gibbose, punctured; clypeus either feebly sinuate or non-sinuate medially, rounded laterally, with thin margin; clypeal margin glabrous or with short bristles laterally. Genae obtusely rounded, sparsely fimbriate, usually protruding beyond eyes; eyes small; frontal suture usually obsolete, sometimes distinctly impressed (at least laterally), rarely elevated laterally. Epipharynx widely rounded laterally, strongly sinuate at front margin; epitorma conical or subelliptical; corypha usually with short spiculae rounded apically; pedia with reduced prophobae and with several stout spinules evenly scattered; chaetopedia short, stout, rather sparse; apophobae sparse, evenly scattered; apotormae weak. Pronotum moderately convex, with dual or even punctures; base with or without margin. Scutellum small, pentagonal, with straight sides parallel basally or rarely with sides curved, narrowly cordiform. Elytra elongate, usually parallel-sided; striae distinct, crenulate or not; interstriae flat, rarely convex, usually sparsely punctate. Fore tibiae distally tridentate and proximally serrulate at outer margin; upper side smooth or almost smooth. Middle and hind tibiae with strong transverse carinae on outer face, apically fimbriate with spinules short and equal. Pygidium with short, rather dense, recumbent setae; apical margin with dense, somewhat elongate setae. Aedeagus with elongate parameres, parameres rounded and membranous apically; membranes rugulose.

Sexual dimorphism: Males with head distinctly gibbose at middle, with less dense punctation on pronotal disc than females; fore tibiae with apical spur often stouter and inwardly curved or hooked apically in males. Distribution: Palaearctic Region, Nearctic Region, and Mexico.