''Agathiceras'' is a subglobose goniatitid from the family

Agathiceratidae Agathiceratidae, as revised, makes up the goniatitid superfamily Agathiceratoidea. Agathiceratidae, which lived from the Upper Carboniferous (Pennsylvanian) to the Middle Permian, combine related genera with subdiscoidal to globular shells that ...

, widespread and locally abundant in

Lower Pennsylvanian The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the ICS geologic timescale, the younger of two subperiods (or upper of two subsystems) of the Carboniferous Period. It lasted from roughly . As with most o ...

Middle Permian The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0. ...

sediments, e.g. the Urals, Sicily, and Texas. ''Agathiceras'', named by Gemmellaro in 1887 from the Middle Permian Sicilian species, '' A. suessi'', has a broadly rounded outer edge, known as the venter, being at the lower side of the animal during life, and a deeply impressed innerside, the dorsum which corresponds with the back or dorsal side of the animal. The sutures are goniatitic with three lateral and one dorsolateral lobes on either side. Those that are external are spatulate, those hidden are V-shaped. The siphuncle is primitive with the septal necks pointing to the rear, a condition known as retrosiphonate. ''Agathiceras'' is thought to be derived from ''Proshumardites'' according to Saunders ''et al''. (1999), which is thought to be derived from ''Dombarites''; all of which are included in the

. ''Dombarites'' is presumed to have its origin in ''

Goniatites ''Goniatites'' is a genus of extinct cephalopods belonging to the family Goniatitidae, included in the superfamily Goniatitaceae. '' Hibernicoceras'' and '' Hypergoniatites'' are among related genera. Species Description The shell is genera ...

'', type genus of the

Goniatitidae Goniatitidae is one of three families included in the ammonoid cephalopod superfamily Goniatitoidea, known from the Lower Mississippian to the Upper Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 millio ...

Species

* '' Agathiceras anceps'' * '' Agathiceras applanatum'' * '' Agathiceras applini'' * '' Agathiceras ciscoense'' * '' Agathiceras contractum'' * '' Agathiceras divisum'' * '' Agathiceras frechi'' * ''

Agathiceras girtyi ''Agathiceras'' is a subglobose goniatitid from the family Agathiceratidae, widespread and locally abundant in Lower Pennsylvanian to Middle Permian sediments, e.g. the Urals, Sicily, and Texas. ''Agathiceras'', named by Gemmellaro in 1887 from ...

'' * '' Agathiceras jilinense'' * '' Agathiceras mediterraneum'' * '' Agathiceras sequaxilirae'' * '' Agathiceras suessi'' * '' Agathiceras sundaicum'' * '' Agathiceras tornatum'' * '' Agathiceras uralicum'' * '' Agathiceras verkhoyanicum'' * '' Agathiceras vulgatum''

References

* Miller, Furnish, and Schindewolf (1960) ; Paleozoic Ammonoidea, in the Treatise on Invertebrate Paleontology, Part L, Ammonoidea; Geological Soc. of America and Univ of Kansas. * Saunders ''et al''. 1999, Evolution of Complexity in Paleozoic Ammonoid Sutures, Supplementary Material; Science, * ;Specific Agathiceratidae Goniatitida genera Fossil taxa described in 1887 Ammonites of North America Pennsylvanian first appearances Guadalupian genus extinctions Paleozoic life of British Columbia Paleozoic life of Nunavut {{Goniatitida-stub