''Johnlongia'' 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 sand shark from the

Cretaceous period The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geologi ...

. 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 Formation (stratigraphy), geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the La ...

. It is presumed piscivorous; however, it forms a clade with an early filter-feeding shark genus, ''

Pseudomegachasma ''Pseudomegachasma'' ("false megamouth") is an extinct genus of 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 is the only known planktivorous ...

''.

References

Prehistoric shark genera Odontaspididae Late Cretaceous fish of North America Cretaceous sharks {{paleo-shark-stub