Otothyropsis Ribeiro, Carvalho & Melo, 2005

Otothyropsis Ribeiro, Carvalho & Melo, 2005: 491 (Type species: O. marapoama Ribeiro, Carvalho & Melo, 2005: 491, by original designation).

Diagnosis. Otothyropsis is diagnosed among the Hypoptopomatinae based on the following non-exclusive synapomorphies: elongated posterior extension of the compound pterotic, which forms de dorsal margin of an augmented lateral opening of the swimbladder capsule (char. 8, independently acquired by Otothyris and Pseudotothyris), reduced upper pharyngeal tooth plate (char. 23), and middorsal series of lateral plates truncated before the caudal fin (char. 32). In addition, Otothyropsis can be distinguished from most other members of the Otothyrini (sensu Schaefer, 1998; except Parotocinclus, Hisonotus, Epactionotus, and New Taxon 3) by the possession of a notch on the postero-dorsal region of the rostral plate (char. 35) and by having enlarged odontodes on the ventral and dorsal margins of the snout (char. 39). Otothyropsis is further differentiated from Pseudotocinclus, Eurycheilichthys, Schizolecis, Otothyris, and Pseudotothyris by the possession of a single median rostral plate (char. 34).