Delturus anguillicaudatus, photo by J.W. Armbruster
Delturus parahybae, photo by K.S. Cummings
Armbruster (1997, 2004) determined that a clade consisting of Delturus and Upsilodus (Upsilodus may be synonymous with Hemipsilichthys gobio) form a monophyletic group sister to all other loricariids. A manuscript is currently in press by myself, Roberto Reis, and Edson Pereira, so limited information is provided here. In my thesis (Armbruster, 1997), I mistakenly referred to the juvenile Delturus I had available as Upsilodus.
Carinotus La Monte 1933
Delturus can be separated from all other loricariids except Hemipsilichthys the presence of a postdorsal ridge made up of raised, median, unpaired plates and the presence of an adipose fin membrane. Hemipsilichthys can be separated from Delturus by not having the posterior membrane of the dorsal fin contacting the anteriormost preadipose plate.