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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 512 described and 23 undescribed species in eight orders. The families and genera within the orders are listed in ...
In most oviparous shark species, an egg case with the consistency of leather protects the developing embryo(s). These cases may be corkscrewed into crevices for protection. The egg case is commonly called a mermaid's purse. Oviparous sharks include the horn shark, catshark, Port Jackson shark, and swellshark. [80] [82]
The whale shark, the world's largest fish, is classified as Endangered. Binding legislation and harvest management strategies... are urgently needed to address the disproportionate impact of fisheries on cartilaginous fishes. – IUCN global study 2010 Threatened sharks are those vulnerable to endangerment (extinction) in the near future. The International Union for Conservation of Nature ...
Carcharhiniformes. Ground sharks, like this blacknose shark, have a nictitating membrane which can be drawn over the eye to protect it. Carcharhiniformes / kɑːrkəˈraɪnɪfɔːrmiːz /, the Requiem sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and ...
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.
A great white shark at Isla Guadalupe, Mexico. The following outline is provided as an overview of and topical guide to sharks: Sharks (superorder Selachimorpha) are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 440 million years ago, before the time of the dinosaurs.
This species of hammerhead shark is the most recently discovered out of the ten species. It was documented by Carter Gilbert in 1967 when a specimen was caught off Charleston, SC.
The megamouth shark is an extremely rare species of deepwater shark, and the smallest of the three filter-feeding sharks. Since its discovery in 1976, only a few megamouth sharks have been seen, with 55 specimens known to have been caught or sighted as of 2012, including three recordings on film.