Saprinillus Kryzhanovskij, 1974

Lackner, Tomáš, 2010, Review of the Palaearctic genera of Saprininae (Coleoptera: Histeridae), Acta Entomologica Musei Nationalis Pragae (suppl.) 50, pp. 1-254 : 191-192

Saprinillus Kryzhanovskij, 1974

Saprinillus Kryzhanovskij, 1974: 106 . Type species: Saprinillus paromaloides Kryzhanovskij, 1974 , original designation.

Saprinillus: Kryzhanovskij in KRYZHANOVSKIJ & REICHARDT (1976) : 216; MAZUR (1984): 83; MAZUR (1997): 249; MAZUR (2004): 96; LACKNER (2009a): 108.

Diagnosis. Body very small for the subfamily (1.40–1.80 mm), cuticle without metallic luster, body sub-cylindrical to elongate oval, convex; clypeus and anterior third of frontal disc rugulose-lacunose, rest of frontal disc with sparse but coarse punctures; frontal stria largely interrupted, forming acute angles behind eyes; pronotal foveae absent; pronotal hypomeron glabrous (in case of S. kryzhanovskyi with extremely short sparse setae). Apical elytral stria absent, sutural stria complete; pre-apical foveae present, well impressed; prosternal process narrowed; both sets of prosternal striae well developed (in the case of Saprinillus kryzhanov- skyi lateral prosternal striae interrupted by antennal cavity); protibia with 5–6 short denticles on outer margin, teeth absent.

This genus has been recently revised by LACKNER (2009a). For the sake of consistency its diagnosis, biology and distribution are repeated here, if slightly altered to fit the style used in this publication. Likewise, since this paper introduces some new terminology, this has also been taken into the account and the relevant parts are duly altered.

Differential diagnosis. Genus Saprinillus stands out from the other genera of Palaearctic Saprininae by its small body size, sub-cylindrical body, coarsely and rugosely granulate clypeus and anterior part of frontal disc, and by the shape of protibia which is without typical articulated triangular teeth and instead is adorned with denticles, growing out directly from the outer margin of protibia. Only few other genera of the Palaearctic Saprininae possess denticles (as opposed to articulated teeth) on the outer protibial margin, namely Microsaprinus , Eremosaprinus , Myrmetes and Turanostyphrus . However, Saprinillus differs significantly from all the above-mentioned genera: from the genus Microsaprinus by the rugulose-lacunose clypeus and anterior third of frontal disc, anteriorly united carinal and lateral prosternal striae (anteriorly ‘open’ in Microsaprinus ), present pre-apical foveae (absent in Microsaprinus ) and by the more elongate, almost cylindrical body; from Eremosaprinus it also differs by the rugulose-lacunose clypeus and anterior third of frontal disc (finely punctate in Eremosaprinus ), present pre-apical foveae (absent in Eremosaprinus ), by the sub-cylindrical body shape (roundly oval in Eremosaprinus ), and the much shorter meso- and metatibiae; from Myrmetes it differs by the same characters as from Eremosaprinus ; furthermore, Myrmetes has almost impunctate dorsal surface; and from the species of the genus Turanostyphrus it differs by the above-mentioned characters, plus asetose elytral epipleuron, bearing setae in Turanostyphrus . On the other hand, it superficially resembles the genus Axelinus , especially by the rugulose-lacunose anterior part of frontal disc, with largely interrupted frontal stria, but differing from it chiefly by the shape of protibia (bearing three large teeth topped with denticles in Axelinus ), and by the more slender metatibiae (thickened in Axelinus ).

Biology. The biology of this genus is poorly documented. The type series of both species were collected in debris under plant Kalidium gracile (Chenopodiaceae) . The specimens from Turkmenistan and Kazakhstan were found in a burrow of a Giant Gerbil ( Rhombomys opimus (Lichtenstein, 1823)) or trapped by a pitfall trap, respectively ( KRYZHANOVSKIJ 1987). LACKNER (2009a) speculated that this taxon might rank amongst inqulines rather than psammophiles, in accordance with KRYZHANOVSKIJ (1987) who discussed the shape of protibia as unfit for the psammophilous habits.

Distribution. Mongolia: South Gobi Aimak, Turkmenistan and Kazakhstan ( MAZUR 1997, LACKNER 2009a).

Species examined. Saprinillus kryzhanovskyi Lackner, 2009 , S. paromaloides Kryzhanovskij, 1974 .

Discussion. Saprinillus belongs probably to the group of the genera (together with Axelinus , Alienocacculus , etc.) that are probably deeply nested within the paraphyletic genus Hypocacculus . It is supported by several ‘weak’ synapomorphies e.g. cylindrical body, rugulose-lacunose frons or interrupted frontal stria. Its monophyly should be tested in the future.