''Johnlongia'' is an extinct
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
sand shark
Sand sharks, also known as sand tiger sharks, gray nurse sharks or ragged tooth sharks, are Lamniformes, mackerel sharks of the family (biology), family Odontaspididae. They are found worldwide in temperate and tropical waters. The three specie ...
from the
Cretaceous period
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of t ...
. It contains two described species, ''J. parvidens'' and ''J. allocotodon'', and possibly a third unnamed species from the
Niobrara Chalk
The Niobrara Formation , also called the Niobrara Chalk, is a geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the Late Cretaceous. It is compose ...
. It is presumed piscivorous; however, it forms a clade with an early filter-feeding shark genus, ''
Pseudomegachasma
''Pseudomegachasma'' ("false Megamouth shark, megamouth") is an extinct genus of Filter feeder, filter-feeding shark that was closely related to the modern sand tiger shark. It is known from Cretaceous strata in Russia and the United States, and ...
''.
References
Prehistoric shark genera
Odontaspididae
Late Cretaceous fish of North America
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