''Archaeolamna'' (from Greek ''arche'' which turned into ''archaeo'' and '' Lamna'', an extinct shark genus) is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of mackerel sharks that lived 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 ...

. It contains three valid species (one with two subspecies) which have been found in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. While it is mostly known from isolated teeth, an associated set of teeth, jaws, cranial fragments, and vertebrae of ''A. kopingensis'' is known from the

Pierre Shale The Pierre Shale is a geologic formation or series in the Upper Cretaceous which occurs east of the Rocky Mountains in the Great Plains, from Pembina Valley in Canada to New Mexico. The Pierre Shale was described by Fielding Bradford Meek, Meek a ...

Kansas Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...

. Teeth of ''A. k. judithensis'' were found with a

plesiosaur The Plesiosauria or plesiosaurs are an Order (biology), order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period (geology), Period, possibly in the Rhaetian st ...

skeleton with bite marks from the Judith River Formation of

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

. It was a medium-sized shark with an estimated total body length of . ''Archaeolamna'' likely had an antitropical distribution, being found in the temperate waters of both hemispheres but absent from the tropical waters around the equator, much like the modern porbeagle shark. A similar distribution has been found for the related '' Cardabiodon''.

Taxonomy

When the family Archaeolamnidae was first named, it contained ''Archaeolamna'', '' Cretodus'', ''

Dallasiella ''Dallasiella'' is an extinct genus of mackerel sharks that lived during the Late Cretaceous. It contains two valid species, ''D. willistoni'' and ''D. brachyodon'', which have been found in North America and Europe. While formerly placed in t ...

'', and ''Telodontaspis''. However, ''Cretodus'' was reassigned to

Pseudoscapanorhynchidae Pseudoscapanorhynchidae is a Family (biology), family of extinct Lamniformes, mackerel sharks that lived during the Cretaceous and potentially the Paleogene. It currently includes ''Cretodus'', ''Eoptolamna'', ''Leptostyrax'', ''Protolamna'', ''P ...

, ''Dallasiella'' was reassigned to Lamniformes ''

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'', and ''Telodontaspis'' was synonymized with '' Cretoxyrhina''. This leaves ''Archaeolamna'' as the sole member of the family.

References

{{Taxonbar, from=Q104851587 Lamniformes Prehistoric shark genera Fossil taxa described in 1992