A shark tooth is one of the numerous teeth of a shark. Sharks continually shed their teeth, and some Carcharhiniformes shed approximately 35,000 teeth in a lifetime. In some geological formations, shark's teeth are a common fossil. These fossils can be analyzed for information on shark evolution and biology, especially because the teeth are often the only part of the shark to be fossilized, in fact fossil teeth comprise much of the fossil record of the Elasmobranchii, extending back hundreds of millions of years.
The most ancient types of sharks date back to 450 million years ago, during the Late Ordovician period, and they are mostly known from their fossilised teeth. The most commonly found fossil shark's teeth are, however, from the Cenozoic (the last 65 million years).
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Famous quotes containing the words shark and/or tooth:
“I have often told you that I am that little fish who swims about under a shark and, I believe, lives indelicately on its offal. Anyway, that is the way I am. Life moves over me in a vast black shadow and I swallow whatever it drops with relish, having learned in a very hard school that one cannot be both a parasite and enjoy self-nourishment without moving in worlds too fantastic for even my disordered imagination to people with meaning.”
—Zelda Fitzgerald (1900–1948)
“With a new familiarity and a flesh-creeping “homeliness” entirely of this unreal, materialistic world, where all “sentiment” is coarsely manufactured and advertised in colossal sickly captions, disguised for the sweet tooth of a monstrous baby called “the Public,” the family as it is, broken up on all hands by the agency of feminist and economic propaganda, reconstitutes itself in the image of the state.”
—Percy Wyndham Lewis (1882–1957)