Tydeus Koch, 1835

Tydeus Koch, 1835:11 –12; Oudemans, 1937: 922 (in part); Kaźmierski, 1989b: 292 (in part). Brachytydeus Thor, 1933: 54 (in part).

Calotydeus Oudemans, 1937: 923 (in part).

Orthotydeus André, 1980: 127

Type species: Tydeus spathulatus Oudemans, 1928 sensu André 2005 .

Remarks. A few Tydeus -like species have clavate or spatulate setae at their posterior idiosomal margin. These were placed in Orthotydeus, as proposed by André (1980). However, Kaźmierski (1989b) redefined Tydeus to include species with such modified setae, and subsequently Orthotydeus was synonymized with Tydeus by André (2005). This genus is characterized by having four pairs of aggenital and four or six pairs of genital setae; epimeral formula 3-1-4-2; leg setal counts: Leg I: 8 (1ω)-4-3-3-1; Leg II: 6-2-2-2-0; Leg III: 5-2-1-1-1; Leg IV: 5-2-1-1-0.