Spurdog

From Wikipedia, the free encyclopedia
Jump to: navigation, search
"Squalus" redirects here. For the submarine called Squalus, see USS Sailfish (SS-192).
Spurdogs
Temporal range: 83–0 Ma
Campanian to Present[1]
Squalus acanthias2.jpg
Squalus acanthias
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Squaliformes
Family: Squalidae
Genus: Squalus
Linnaeus, 1758

Squalus is a genus of dogfish sharks in the family Squalidae. Commonly known as spurdogs, these sharks are characterized by smooth dorsal fin spines, teeth in upper and lower jaws similar in size, caudal peduncle with lateral keels; upper precaudal pit usually present, and caudal fin without subterminal notch. In spurdogs, the hyomandibula (the bone connecting the braincase to the jaws) is oriented at a right angle to the neurocranium, while in other sharks, the hyomandibula runs more parallel to the body. This led some to think that the upper jaw of Squalus would not be as protractile as the jaws of other sharks. However, a study that compared different jaw suspension types in sharks showed that this is not the case and that Squalus is quite capable of protruding its upper jaw during feeding.[2]

The name comes from squalus, the Latin for shark; this word is the root for numerous words related to sharks such as squaline and scientific names for sharks, such as the order Squaliformes.

Species[edit]

There are currently 30 recognized species in this genus:

See also[edit]

References[edit]

  1. ^ Sepkoski, J.J.Jr (2002). "A Compendium of Fossil Marine Animal Genera". Bulletins of American Paleontology, 363: 1-560. 
  2. ^ Wilga, C.D., Motta, P.J. & Sanford, C.P. (2007): Evolution and ecology of feeding in elasmobranchs. Integrative and Comparative Biology, 47 (1): 55-69.
  3. ^ a b c d e Viana, S.T.d.F., Carvalho, M.R.d. & Gomes, U.L. (2016): Taxonomy and morphology of species of the genus Squalus Linnaeus, 1758 from the Southwestern Atlantic Ocean (Chondrichthyes: Squaliformes: Squalidae). Zootaxa, 4133 (1): 1-89.
  4. ^ Viana, S.T.d.F. & Carvalho, M.R.d. (2016): Redescription of Squalus acutipinnis Regan, 1908, a Valid Species of Spiny Dogfish from Southern Africa (Chondrichthyes: Squaliformes: Squalidae). Copeia, 104 (2): 539-553.