Can be easily distinguished from all other species of the genus Trichomycterus from western and southern South America by possessing an autapomorphic thickened transverse skin on the ventral surface of the head. Differs further from other congeners except Trichomycterus corduvensis from Argentina and Trichomycterus tiraquae from Bolivia by the combination of the following characters: presence of spatulate incisiform premaxillary teeth; presence of large and rounded papilla-like structures on the trunk of the body; the continuous segment of the laterosensory canal within the frontal with the presence of a segment between pores 2 and 6; and laterosensory canal on trunk with 4 to 6 pores. Can be differentiated from Trichomycterus tiraquae and Trichomycterus corduvensis by the shape of the maxilla, which has a short anterior process that is shorter than the main axis of the bone and is anteriorly oriented (vs. anterior process enlarged and equal to, or longer than

the main axis of the bone and with an anterolateral orientation); mesethmoid shaft narrower than the width of the lateral cornua (vs. shaft equal to or wider than width of lateral cornua). Differ also from Trichomycterus tiraquae by having prepelvic length 58.7-61.0% of SL (vs. 56.6-57.6), head width 19.1-22.8% of SL (vs. 17.4-18.9); the submaxillary barbel length 23.9-37.5% of SL (vs. 43.3-54.8) (Ref. 72406).

Description: Dorsal fin v,9; Anal fin vi,5; Pectoral fin i8; Pelvic fin i4 (Ref. 72406).