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The first shark-like chondrichthyans appeared in the oceans 400 million years ago, [1] developing into the crown group of sharks by the Early Jurassic. [2] Listed below are extant species of shark. Sharks are spread across 556 described and 23 undescribed species in eight orders. The families and genera within the orders are listed in ...
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Rising demands for shark products has increased pressure on shark fisheries, but little monitoring or management occurs of most fisheries. [7] Major declines in shark stocks have been recorded over the past few decades; some species had declined over 90% and population declines of 70% were not unusual by 1998. [8]
The most widely known species still surviving is the frilled shark, known as a living fossil, along with the Southern African frilled shark, found along coastal areas of South Africa. Several extinct species are known. †Crassodontidanidae †Crassodontidanidae: 4 8 Extinct: Hexanchidae: Cow sharks: 3 extant 5 extinct 5 extant 31 extinct
Extinct white shark tooth. Study of white shark taxonomy is complicated by nomenclature and repeated taxonomic reassignments of various species. C. hastalis, C. subserratus , and C. planus traditionally were placed in Isurus , [ 3 ] given their superficial similarity to the teeth of mako sharks, leading many modern shark tooth collectors to ...
The shark is among the 25 "most wanted lost" species that are the focus of Global Wildlife Conservation's "Search for Lost Species" initiative. [2] The Pondicherry has been spotted in rivers in India in the late 2010s. [3] A Pondicherry shark was caught in the Menik Ganga (river) in SE Sri Lanka in 2011. It was photographed and released alive.
Otodus is an extinct, cosmopolitan genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name Otodus comes from Ancient Greek ὠτ- ( ōt- , meaning "ear") and ὀδούς ( odoús , meaning "tooth") – thus, "ear-shaped tooth".
Using the reconstruction, Eastman identified the many extinct shark species and found that their fossils are actually different tooth types of O. mantelli, which he all moved into the species. [ 19 ] [ 7 ] This skeleton, which Sternberg had sold to the Ludwig Maximilian University of Munich , was destroyed in 1944 by allied bombing during World ...