About all Sharks

Essay by shaunJunior High, 9th gradeA+, March 1996

download word file, 3 pages 4.1

Downloaded 108 times

ABOUT ALL SHAKES

BY. SHAUN LEVY

SHARK FAMILIES:

There are more then 350 know species of sharks today, which can all be placed under 8 scientific orders that contain 30 families. They are placed into these categories by their shared characteristics, this is called taxonomy. The more closeley related species are placed in another family in the order.

SQUAINIFORMES: The angel shark as they are commonly known are characterized by their RAY like flattened bodies. This order has one family which is called SQUATINDAE that contains about 13 species. The maximum size that can be attained by any one of these species is 4-6 feet in length.

PRISTIOPHORIFORMES: These shark are known as the saw shark. This order has only has one family PHISTOPHORIFORMES which contains five species. These sharks are easy to recongnize due to the fact that they posses an ellongated blade like snout that is lined with sharp teeth along the edges, thus, the name saw sharks.

SQUALIFORMES: The order possesses three family which consist of about 82 species. These sharks are characterized by their slender, cylinder-shaped bodies, long snouts with shortened mouths.

HEXANCHIFORMES: The Hexanchiformes or cow sharks, comprise of two families. Recognized by their six or seven pairs of gill slits, there sharks can often be found in deep water. The frilled shark (CHLAMYDISELACHUS ANGUINEUS) who's appearance is quite unmistakable due to it's 'eel' like appearance, is perhaps one the strangest shark that exist today.

FOSSIL RECORD:

Shark fossil record is fargmentery at best. Most fossils found so far consist of nothing but teeth in some cases a few vertebra have been found. This is rare due to the fact that sharks have bones instead, they have cartiladge which countrary common belief is rather solid. In the rarest of cases complete fossil have...