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).
Read more about Shark Tooth: Function, Counting, Tool Use By Humans, See Also
Famous quotes containing the words shark and/or tooth:
“Oh, the shark has pretty teeth, dear
And he shows them pearly white
Just a jackknife has Macheath, dear
And he keeps it out of sight.”
—Bertolt Brecht (18981956)
“If only one tooth aches, rejoice that not all of them ache.... If your wife betrays you, be glad that she betrayed only you and not the nation.”
—Anton Pavlovich Chekhov (18601904)