trigonocephalus, Sorubim Miranda Ribeiro [A. de] 1920:12, Unnum. Pls. 10-11 [Peixes (excl. Characinidae) No. 58 (Annexo 5); ref. 3727] Arinos River, downstream from the mouth of Preto River, Juruena drainage, Tapajós basin, Porto Velho, Diamantino, Mato Grosso, Brazil, 14°05'32.25"S, 56°19'26.44"W. Holotype (unique): MNRJ 882 (lost). Type catalog: Miranda Ribeiro 1955:404 [ref. 12732], Ferraris 2007:342 [ref. 29155]. •Valid as Sorubim trigonocephalus Miranda Ribeiro 1920 -- (Burgess 1989:282 [ref. 12860], Littmann et al. 2000:902 [ref. 25063], Littmann et al. 2001:2 [ref. 25400], Lundberg & Littmann in Reis et al. 2003:442 [ref. 27061], Littmann 2007:16 [ref. 29028], Ferraris 2007:342 [ref. 29155], Ohara & Neuhaus 2016:292 [ref. 34536] with change in type locality, Grant 2021:133 [ref. 38702]). Current status: Valid as Sorubim trigonocephalus Miranda Ribeiro 1920. Pimelodidae. Distribution: South America: Tapajós and Xingu River basins, southern tributaries to lower Amazon system (Brazil). Habitat: freshwater.