Elasmobranchii

Elasmobranchii (/ɪˌlæzməˈbræŋkiaɪ/) adalah subkelas dari Chondrichthyes atau ikan cartilaginous, termasuk hiu (superorder Selachii) dan pari, skate, dan sawfish (superorder Batoidea). Anggota subkelas ini bercirikan mempunyai empat sampai tujuh pasang bukaan insang dipermukaan tubuh, Sirip perutsl yang kaku dan sisik kecil (placoid scale).

Elasmobranchii Rentang waktu: Wenlock–Recent PreЄ Є O S D C P T J K Pg N
Hiu putih (Carcharodon carcharias)
Klasifikasi ilmiah
Domain:	Eukaryota
Kerajaan:	Animalia
Filum:	Chordata
Kelas:	Chondrichthyes
Subkelas:	Elasmobranchii Bonaparte, 1838
Superorders
Batoidea Selachimorpha

Elasmobranchs lack swim bladders, and maintain buoyancy with oil that they store in their livers. Some deep sea sharks are targeted by fisheries for this liver oil, including the school, gulper and basking sharks (pictured). All three of these species have been assessed by the IUCN as vulnerable due to overfishing.

Radiation of elasmobranchs, based on Michael Benton, 2005.

From a practical point of view the life-history pattern of elasmobranchs makes this group of animals extremely susceptible to over fishing. It is no coincidence that the commercially exploited marine turtles and baleen whales, which have life-history patterns similar to the sharks, are also in trouble.

Fosil elasmobranch termuda berasal dari masa Devonian sampai masa Cretaceous, atau lebih awal. Banysk spesies punah pada masa Permian dan ada semburan Radiasi adaptasi pada jaman Jurassic.