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:
“They will tell you tough stories of sharks all over the Cape, which I do not presume to doubt utterly,—how they will sometimes upset a boat, or tear it in pieces, to get at the man in it. I can easily believe in the undertow, but I have no doubt that one shark in a dozen years is enough to keep up the reputation of a beach a hundred miles long.”
—Henry David Thoreau (1817–1862)
“If she must teem,
Create her child of spleen, that it may live
And be a thwart disnatured torment to her!
Let it stamp wrinkles in her brow of youth,
With cadent tears fret channels in her cheeks,
Turn all her mother’s pains and benefits
To laughter and contempt, that she may feel
How sharper than a serpent’s tooth it is
To have a thankless child!”
—William Shakespeare (1564–1616)