Xenopygus Bernhauer

Xenopygus Bernhauer, 1906: 196 [species included: X. analis (Erichson, 1840), X. bicolor (Laporte, 1835)]; full taxonomic history in Caron et al. 2016.

Leptodiastemus Bernhauer, 1934: 215 [described as subgenus of Dysanellus, species included: Dysanellus (L.) excellens Bernhauer, 1934]; type species Dysanellus (L.) excellens Bernhauer, 1934; fixed by monotypy. New synonymy.

Type species: Xenopygus analis (Erichson, 1840); Blackwelder 1943: 451.

Diagnosis. Xenopygus can be distinguished from all other Xanthopygina based on the combination of the following characters: antennomeres 6–10 transverse (in contrast to several species of superficially similar Oligotergus that have antennomeres 6–10 subquadrate or longer than wide); labial palpomere 3 truncate and not securiform; head narrow (much wider in the related genus Xanthopygus); nuchal ridge developed (absent in some Xanthopygina genera); neck with punctures and micropunctures (punctation absent in most Xanthopygina genera); postcoxal process present (absent in Oligotergus); abdominal terga III–IV or III–V with arch-like carina (absent in some closely related Xanthopygina genera).