Can be diagnosed from non-Hypoptopomatinae loricariids by having the ventral surface of the coracoid with an exposed area supporting a few odontodes laterally, close to the pectoral-fin insertion, and, except from Kronichthys, by having the odontodes on the ventral surface of the pelvic-fin unbranched ray distinctly bent and turned mesially. Differs from all hypoptopomatines, except Parotocinclus prata, by having the premaxilla and dentary tooth series strongly curved mesially, in such a way that the mesial portion of the tooth series in both sides are turned and run parallel to each other vs. tooth series straight or slightly curved). It is also distinguished from the remaining hypoptopomatines, except Pseudotocinclus, by having the caudal peduncle distinctly quadrangular in cross-section (vs. caudal peduncle ovoid in cross-section), and except from Gymnotocinclus by having the anterior margin of the snout devoid of dermal plates (Ref. 90155).