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

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

, widespread and locally abundant in Lower Pennsylvanian to

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 ( Blaine Formation). ''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 generally ...

'', type genus of the

Goniatitidae Goniatitidae is one of three families included in the Ammonoidea, ammonoid cephalopod superfamily Goniatitoidea, known from the Lower Mississippian (geology), Mississippian to the Upper Permian. They have sutures that form 8 lobes and characteris ...

Species

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

Agathiceras girtyi ''Agathiceras'' is a subglobose goniatitida, goniatitid from the family Agathiceratidae, widespread and locally abundant in Lower Pennsylvanian to Middle Permian sediments, e.g. the Urals, Sicily, and Texas (Blaine Formation). ''Agathiceras'', n ...

'' * '' 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 The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, 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