Tychobythinus Ganglbauer, 1896

Besuchet, Claude, Cuccodoro, Giulio & Sabella, Giorgio, 2013, On the genera Acanthobythus Normand, 1930 and Ceratobythus Normand, 1932 (Coleoptera: Staphylinidae: Pselaphinae), Revue suisse de Zoologie 120 (2), pp. 271-280 : 272

Tychobythinus Ganglbauer, 1896

Tychobythinus Ganglbauer, 1896: 170 ; type species: Bythinus ottonis Ganglbauer, 1896 (subsequent designation).

Acanthobythus Normand, 1930: 163; type species: Bythoxenus araneipes Normand, 1930 (monotypy).

Ceratobythus Normand, 1932: 15 ; type species: Bythoxenus monoceros Normand, 1932 (monotypy) syn. nov.

COMMENTS: Normand in 1930 and 1932, described respectively Acanthobythus and Ceratobythus as new subgenera of Bythoxenus Motschulsky, 1860 . Jeannel (1956) raised Acanthobythus to genus rank, arguing that it was certainly a distinct lineage from both his Anopsibythus Jeannel, 1956 (erected to accommodate five anophthalmous Algerian species and presently a synonym of Tychobythinus ) and Ceratobythus , and « also completely unrelated » to Bythoxenus .

In both, the World catalogue of the genera of Pselaphinae ( Newton & Chandler, 1989) and Pselaphinae in the Catalogue of Palaearctic Coleoptera ( Löbl & Besuchet, 2004) , Ceratobythus is listed as a valid while Acanthobythus is a synonym of Tychobythinus . The latter placement has however never been discussed, neither A. araneipes explicitly transferred.

Acanthobythus and Ceratobythus share with the 89 species-rich Holarctic genus Tychobythinus the pronotal and elytral foveal systems, as well as most other external characters, such as the antennal scape much longer than wide, narrowed and flattened at basal third and widest at distal third, the maxillary palpi with segments II and III bearing many prominent tubercles and the apical segment distinctly longer than wide and widest at basal third, and prominent tubercles on the anterior margin of protrochanters and profemora. In fact Acanthobythus and Ceratobythus differ from each other and from members of Tychobythinus only by head features. The conformation of their aedeagi also fits within the variation observed in Tychobythinus . Therefore, we consider that there is no justification to maintain them as distinct genera.