The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order of
shark
Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...
s commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the great white as well as less familiar ones, such as the goblin shark and megamouth shark.
Members of the order are distinguished by possessing two dorsal fins, an
anal fin
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...
, five gill slits, eyes without nictitating membranes, and a mouth extending behind the eyes. Species in two families of Lamniformes – Lamnidae and Alopiidae – are distinguished for maintaining a higher body temperature than the surrounding waters.
Members of the group include macropredators, generally of medium-large size, including the largest macropredatory shark ever, the extinct '' Otodus megalodon,'' as well as large
planktivore
A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and i ...
s.
Although some authors have argued that the Late Jurassic '' Palaeocarcharias'' should be considered the oldest known lamniform, this is disputed. The earliest unambiguous records of lamniformes are from the Early Cretaceous. Lamniformes underwent a major adaptive radiation during the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
and became prominent elements of oceanic ecosystems. They reached their highest diversity during the Late Cretaceous, but severely declined during the K-Pg extinction, before rebounding to a high but lower diversity peak during the Paleogene. Lamniformes have severely declined over the last 20 million years, with only 15 species alive today, compared to over 290 extant species in the Carcharhiniformes, which have evolved into medium and large body sizes during the same timeframe. The causes of the decline are uncertain, but are likely to have involved both biotic factors like competition and non-biotic factors like temperature and sea level.
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...
Gill
A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...
Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
cladogram
A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...
showing relationships within Lamniformes. The topology of extant families is based on Vella & Vella (2020) and the placements of Cretoxyrhinidae and Otodontidae are based on Ferrón (2017), Cooper (2020), and Greenfield (2022).
Sustainable consumption
In 2010,
Greenpeace International
Greenpeace is an independent global campaigning network, founded in Canada in 1971 by a group of environmental activists. Greenpeace states its goal is to "ensure the ability of the Earth to nurture life in all its diversity" and focuses its ...