Rhaphiodon, Agassiz, 1829

TOLEDO-PIZA, MÔNICA, 2000, The Neotropical Fish Subfamily Cynodontinae (Teleostei: Ostariophysi: Characiformes): A Phylogenetic Study and a Revision of Cynodon and Rhaphiodon, American Museum Novitates 3286, pp. 1-1 : 1-

Rhaphiodon is monotypic, represented by a highly specialized species R. vulpinus . The autapomorphies characterizing Rhaphiodon vulpinus are as follows:

1. Anterior shelf of frontal having a straight edge (character 22–state 3).

2. Spines on dorsal margin of gill­rakers on first ceratobranchial not conspicuously larger than spines on lateral surface of gill­raker, independently acquired in the formed by Hydrolycus tatauaia , H. armatus , and H. scomberoides ) (character 39).

3. Highly modified lateral process of second vertebra (character 45 ­ state 3).

4. Anterior elongation of bladelike portion of tripus (character 47).

5. Posterior portion of transformator process of tripus forming a 90° angle relative to its anterior portion, and ending in an enlarged rectangular bony plate (character 48).

6. Further enlargement of ventral process of fifth vertebra (character 51–state 2).

7. Highly modified fifth pleural rib (character 52).

8. Lack of an anterodorsal projection at anterior portion of cleithrum (character 62– state 2).

9. Presence of myorhabdoi (character 67).

10. Presence of fringelike appendices along lateral surface of posterior chamber of gasbladder (character 69).

Ambiguous features for this species:

A 1. Process on a shaft of hyomandibula, also present in Hydrolycus (character 26).

A 2. Metapterygoid teeth present, also present in Hydrolycus (character 28).

A 3. Lack of attachment of Baudelot’s ligament to lateral process of second vertebra (character 54).