Tarphyceras

Taxobox
fossil_range = L Ordovician
name = "Tarphyceras"


regnum = Animalia
phylum = Mollusca
classis = Cephalopoda
subclassis = Nautiloidea
ordo = Tarphycerida
familia = Tarpyceratidae
genus = " Tarphyceras "
genus_authority = Hyatt 1894

"Tarphyeras" is a genus of tarphyceratid with whorls rounded in cross section, having a deeply impressed dorsum and a ventral to subcentral siphuncle, known from the Lower Ord (U Canad) of North America. It differs from "Campbelloceras" in that "Campbelloceras" is only slightly impressed, from "Centrotarphyceras" in that "Centrotarphyceras" is subquadrate and has a central siphuncle, and from "Trocholites" in that although "Trocholites" is subcircular in cross section, the siphuncle is subdorsal.

"Taphyceras" may be derived from "Campbelloceras" through development of tighter coiling and a deeper impression along with a smaller siphuncle that may be further offset from the venter.

"Tarphyceras" was named by Hyatt in 1894.

References

* Furnish and Glenister 1964,Nautiloidea - Tarphycerida, K354, in The Treatise on Invertebrate Paleontology Vol K; Teichert and Moore, (eds) GSA and U of Kansas Press,1964