from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. A taxonomic class within the subphylum Vertebrata — the cartilaginous fishes.
from the GNU version of the Collaborative International Dictionary of English
- n. the class of fishes comprising the cartilaginous fishes, which includes the sharks.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. cartilaginous fishes
I'm reading the new Journal of Vertebrate Paleontology, and have so far made my way through three articles on fossil sharks: "Exceptional preservation of the white shark Carcharodon (Lamniformes, Lamnidae) from the early Pliocene of Peru"; "The spine-brush complex in symmoriiform sharks (Chondrichthyes; Symmoriiformes), with comments on dorsal fin modularity"; and "Pectoral anatomy of Tribodus limae (Elasmobranchii: Hybodontiformes) from the Lower Cretaceous of northeastern Brazil."
As for the remainder of yesterday, I read through a couple of papers in the June Journal of Vertebrate Paleontology — — "A reassessment of some poorly known turtles from the Middle Jurassic of China, with comments on the antiquity of extant turtles" and "A rare Danian (Early Paleocene) Chlamydoselachus (Chondrichthyes: Elasmobranchi) from the Takatika Grit, Chatham Islands, New Zealand."
Sharks, ray, and guitarfish all belong to the subclass Elasmobranchii within the cartilaginous fish class Chondrichthyes.
While I’m not aware of any study that has been carried out that points to the prevalence of malformation of the eye in sharks, based upon what we know about mammals, it is indeed possible that such a condition exists among Chondrichthyes.