Title
Pharyngeal denticles (placoid scales) of sharks, with notes on the dermal skeleton of vertebrates
Title Variants
Alternative:
Notes on the dermal skeleton of vertebrates
Related Titles
Series:
American Museum novitates, no. 2415
By
Nelson, Gareth J.
Type
Book
Material
Published material
Publication info
New York, N.Y American Museum of Natural History [1970]
Notes
Title from caption.
"May 21, 1970."
"Within the buccopharyngeal cavity of many Recent sharks, there occurs a well-developed dermal skeleton, consisting of numerous, independent, non-growing denticles (placoid scales). It is apparent that the extent of this dermal skeleton, from the jaw margin to the pharyngo-esophogeal boundary, is a feature primitive for the Gnathostomata. Secondary reductions in the extent of this dermal skeleton are apparent in some Recent sharks. In others, pharyngeal denticles participate in the formation of specialized structures (pharyngeal pads), apparently analogous to the consolidated pharyngeal tooth plates of teleostomes. These observations lead to the hypothesis that the dermal skeleton of modern elasmobranchs is primitively subdivided, that is, in a primary micromeric condition. The relevance of this hypothesis is discussed in the context of a comparative theory of the dermal skeleton of vertebrates"--P. 24.
Subjects
Anatomy
,
Evolution
,
Holocene
,
Paleontology
,
Pharynx
,
Scales (Fishes)
,
Sharks
,
Sharks, Fossil
,
Vertebrates
Call Number
QL1 .A436 no.2415, 1970
Language
English
Identifiers
OCLC:
45502106
Find in a local library
Download MODS