Cordylancistrus Isbrücker, 1980


Cordylancistrus torbesensis, photo by J.W. Armbruster

Cordylancistrus platycephalus, photo by J.W. Armbruster

TAXA LIST

  • The subgenus Cordylancistrus is appears much the same as Chaetostoma except with a wider head, longer cheek odontodes, and plates on the snout. The genus is not likely to be monophyletic as all of the species ascrtibed to it are quite different in appearance. In fact, some of them share a synapomorphy with Chaetostoma, enlarged papillae behind the dentaries, but specimens were not available for analysis in Armbruster (2004).  The following is an excerpt from Armbruster (1997).

    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


    SPECIES

    DIAGNOSIS

    Cordylancistrus is not currently diagnosable and may be paraphyletic.


    COMPARISONS

    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.


    DISTRIBUTION

    From high montane streams and rivers of the Andes from Venezuela to Ecuador. Localities are sporadic either indicating a lack of collectin effort (not likely) or the non-monophyletic nature of the genus (much more likely).


    LITERATURE CITED

    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.


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