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  2. Shark tooth - Wikipedia

    en.wikipedia.org/wiki/Shark_tooth

    Any fossils, including fossil shark teeth, are preserved in sedimentary rocks after falling from their mouth. [13] The sediment that the teeth were found in is used to help determine the age of the shark tooth due to the fossilization process. [15] Shark teeth are most commonly found between the Upper Cretaceous and Tertiary periods. [16]

  3. Megalodon - Wikipedia

    en.wikipedia.org/wiki/Megalodon

    The shark was an opportunist and piscivorous, and it would have also gone after smaller fish and other sharks. [52] Many whale bones have been found with deep gashes most likely made by their teeth. [ 28 ] : 75 Various excavations have revealed megalodon teeth lying close to the chewed remains of whales, [ 28 ] : 75 [ 30 ] and sometimes in ...

  4. Fish jaw - Wikipedia

    en.wikipedia.org/wiki/Fish_jaw

    Some fish like carp and zebrafish have pharyngeal teeth only. [30] [31] Sea horses, pipefish, and adult sturgeon have no teeth of any type. In fish, Hox gene expression regulates mechanisms for tooth initiation. [32] [33] While both sharks and bony fish continuously produce new teeth throughout their lives, they do so via different mechanism.

  5. Ancient shark-like fish appeared much earlier than ... - AOL

    www.aol.com/ancient-shark-fish-appeared-much...

    A handful of fossil teeth from a completely new species suggests the creatures emerged some 440 million years ago. Ancient shark-like fish appeared much earlier than previously thought – study ...

  6. Fossil hunters find different halves of same ancient shark ...

    www.aol.com/fossil-hunters-different-halves-same...

    The pieces are now reunited, creating a single 5.5-inch-long, 5.1-inch-wide tooth that came from one of the world’s most fearsome predators — a prehistoric shark that reached nearly 60 feet in ...

  7. Shark - Wikipedia

    en.wikipedia.org/wiki/Shark

    Shark teeth are embedded in the gums rather than directly affixed to the jaw, and are constantly replaced throughout life. Multiple rows of replacement teeth grow in a groove on the inside of the jaw and steadily move forward in comparison to a conveyor belt; some sharks lose 30,000 or more teeth in their lifetime. The rate of tooth replacement ...

  8. Shark anatomy - Wikipedia

    en.wikipedia.org/wiki/Shark_anatomy

    Teeth are replaced every two weeks, approximately. [10] The shape of the teeth determine the diet of the shark. For instance, a shark with flat teeth are used for crushing shellfish, pointed teeth are used for gripping fish, while the notoriously sharp teeth with jagged edges are used for large prey. [10]

  9. Chondrichthyes - Wikipedia

    en.wikipedia.org/wiki/Chondrichthyes

    The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The eyes have a tapetum lucidum. The inner margin of each pelvic fin in the male fish is grooved to constitute a clasper for the transmission of sperm. These fish are widely distributed in tropical and temperate waters. [15]