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The selected pictures are what we believe to be the best pictures on Wikipedia related to sharks.Any image that is featured or valued on the English Wikipedia, or featured, valued or considered high quality on Wikimedia Commons, and is used in one or more articles within the scope of WikiProject Sharks, automatically qualifies, and may be added below.
Sharkbook is a global database for identifying and tracking sharks, particularly whale sharks, using uploaded photos and videos.In addition to identifying and tracking sharks, the site allows people to "adopt a shark" and get updates on specific animals.
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]
Shark teeth similar to modern hexanchids and echinorhinids are known from Devonian deposits in Antarctica and Australia, as well as Permian deposits in Japan. If these are in fact hexanchids, this may be the only extant order of elasmobranchs to have survived the Permian extinction (and by extension, the oldest extant order of elasmobranchs).
The really dark shark teeth, Dunn said, are millions of years old and more commonly found. The lighter teeth, beige or pearly in color, fell out more recently.
The whale shark (Rhincodon typus) is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of 18.8 m (61.7 ft). [8] The whale shark holds many records for size in the animal kingdom, most notably being by far the most massive living non-cetacean animal.
[34] [35] [36] Shark teeth are embedded in the gums rather than directly affixed to the jaw as in some fish. [37] Shark teeth form within the jaw move outward in rows until they are eventually dislodged in a manner similar to a conveyor belt. [38] Their scales, called dermal denticles, and teeth are homologous organs. [39]
Engraved on the tooth is a picture of the ship Francis, which artist Fred Myrick served on during the early 1800s. Now, sperm whales are protected under the Marine Mammal Protection Act. So, in ...