Cordylancistrus torbesensis, photo by J.W. Armbruster
Cordylancistrus platycephalus, photo by J.W. Armbruster
Mouth of Cordylancistrus platycephalus, white line indicates the enlarged dentary papilla that was thought to be a synapomorphy by Armbruster (2004) for Chaetostoma, but which might indicate the paraphyletic nature of Cordylancistrus. Photo by J.W. Armbruster
Cordylancistrus is not currently diagnosable and may be paraphyletic.
Like the rest of the Chaetostoma group, Cordylancistrus differs from all Ancistrini
on the basis of a lack of odontodes on the nuchal plate and dorsal-fin
spinelet and 8+ dorsal-fin rays. Cordylancistrus differs from
the Chaetostoma by having plates on the snout and longer cheek odontodes (see Chaetostoma for more information), from Dolichancistrus
by lacking a single, greatly elongate cheek odontode (all cheek odontodes
are relatively short) and by having short pectoral-fin rays in breeding
males (vs. long), and from Leptoancistrus
by lacking a single, greatly
elongate cheek odontode (all cheek odontodes are relatively short) and
by having adipose and anal fins.
From high montane streams and rivers of the Andes from Venezuela to
Localities are sporadic either indicating a lack of collectin effort (not likely) or the non-monophyletic nature of the genus (much more likely).
Armbruster, J.W. 1997. Phylogenetic relationships of the sucker-mouth
armored catfishes (Loricariidae) with particular emphasis on the Ancistrinae,
Hypostominae, and Neoplecostominae. Unpubl. Ph.D. dissertation. University
of Illinois, Urbana-Champaign. 409 pp.