1819 by Italian Zoologist Saverio Macri (1754–1848); Squalus elephas, by Charles Alexandre Lesueur in 1822; Squalus rashleighanus, by Jonathan Couch in 1838; Squalus cetaceus, by Laurens Theodorus Gronovius in 1854; Cetorhinus blainvillei by the Portuguese biologist Felix Antonio de Brito Capello (1828–1879) in 1869; Selachus pennantii, by Charles John Cornish in 1885; Cetorhinus maximus infanuncula, by the Dutch Zoologists Antonius Boudewijn Deinse (1885–1965) and Marcus Jan Adriani (1929–1995) in 1953; and Cetorhinus maximus normani, by Siccardi in 1961. Evolutionary history The oldest known members of Cetorhinidae are members of the extinct genus Keasius, from middle Eocene of Antarctica, the Eocene of Oregon and possibly the Eocene of Russia. Members of the modern genus Cetorhinus appear during the Miocene, with members of the modern species appearing during the Late Miocene. The association of Pseudocetorhinus from the Late Triassic of Europe with Cetorhinidae is doubtful. Range and habitat The basking shark is a coastal-pelagic shark found worldwide in boreal to warm-temperate waters. It lives around the continental shelf and occasionally enters brackish waters. It is found from the surface down to at least . It prefers temperatures of , but has been confirmed to cross the much-warmer waters at the equator. It is often seen close to land, including in bays with narrow openings. The shark follows plankton concentrations in the water column, so is often visible at the surface. It characteristically migrates with the seasons. Anatomy and appearance The basking shark regularly reaches in length with some individuals reaching . The average length of an adult is around weighing about . Historical sightings suggest basking sharks around in length, including three basking sharks estimated at ~40 fod () and a one ~45 fod () were reported between 1884 and 1905, but these visual estimates lack good evidence. A specimen trapped in a herring net in the Bay of Fundy, Canada, in 1851 has been credited as the largest recorded. Its weight has been estimated at . A study looking at the growth and longevity of the basking shark suggested that individuals larger than ~ are unlikely. This is the second-largest extant fish species, after the whale shark. They possess the typical shark lamniform body plan and have been mistaken for great white sharks. The two species can be easily distinguished by the basking shark's cavernous jaw, up to in width, longer and more obvious gill slits that nearly encircle the head