''Asaphus expansus'' () is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

of the asaphid

trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...

genus '' Asaphus''. It was previously classified as ''Entomostracites expansus'' before being split off into its own genus.

References

Trilobites of Asia Asaphidae Ordovician trilobites {{asaphida-stub