| 词条 | Agathiceras |
| 释义 |
| fossil_range = | image = | image_caption = | regnum = Animalia | phylum = Mollusca | classis = Cephalopoda | subclassis = Ammonoidea | ordo = Goniatitida | subordo = Goniatitina | superfamilia = Goniatitaceae | familia = Agathiceratidae | genus = Agathiceras | genus_authority = Gemmellaro 1887 | subdivision_ranks = | subdivision = }} 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 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 dosolateral 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 Dombaties; all of which are included in the Agathiceratidae. Dombarites is presumed to have its origin in Goniatites, type genus of the GoniatitidaeSpecies
References
1. ^{{Cite journal|author=Zuren Zhou |year=2017 |title=Permian basinal ammonoid sequence in Nanpanjiang area of South China—possible overlap between basinal Guadalupian and platform-based Lopingian |journal=Journal of Paleontology |volume=91 |issue=S74 |pages=1–95 |doi=10.1017/jpa.2016.128 }} {{Taxonbar|from=Q4189385}}{{Goniatitida-stub}} 8 : 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 |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。