Acanthodiscus
{{Short description|Genus of molluscs (fossil)}}
{{Automatic taxobox
| fossil_range = Hauterivian
~{{fossil range|133|130}}
| taxon = Acanthodiscus
| authority = Uhlig 1905
| subdivision_ranks = Species
| subdivision = * A. magnificus {{small|Imlay 1938}}
- A. marocanus
- A. octagonus
- A. ottmeri
- A. radiatus {{small|Bruguiére 1792}}
- A. rollieri
- A. schmidtii
- A. subradiatus {{small|Uhlig 1910}}
| type_species = Acanthodiscus radiatus
}}
Acanthodiscus is an extinct ammonoid cephalopod genus from the order Ammonitida and included in the persphinctacean family Berriasellidae. The type species, named by Bruguière, 1792, is Acanthodiscus radiatus.[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=14510 Acanthodiscus] at Fossilworks.org
Description
The shell of Acanthodiscus (A. radiatus) is of modest size, slightly more than {{convert|14|cm|in}} in diameter, coiled with the outer whorl covering about a third of the next inner whorl. The lower (2/3) flanks bear strong, wide spaced, radial ribs with large nodes at either end, and become weaker on the mature body chamber. Outer flanks (approx. 1/3) slope toward a narrow, flat to concave venter lined on either side by a series of smaller nodes. the mature whorl section is higher than wide.
Biostratigraphic significance
Acanthodiscus is found in shallow water sediments in both the Tethyan and Boreal realms where it is used as an index fossil. In fact, the International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of Acanthodiscus radiatus, the first species of the genus, as the defining biological marker for the start of the Hauterivian stage of the Cretaceous, ~132.9 million years ago.
Species
- A. radiatus; type species
- A. marocanus
- A. octagonus
- A. ottmeri
- A. rollieri
- A. schmidtii; Found on the Antarctic Peninsula
- A. subradiatus
Distribution
Acanthodiscus fossils can be found in the Agrio Formation of the Neuquén Basin, Argentina. Also in the Macanal Formation of the Eastern Ranges of the Colombian Andes, fossils of Acanthodiscus have been found.Piraquive et al., 2011, p.204
Other occurrences of the genus are in:
- Abundancia Formation, Chile
- Guchuochun Formation, China
- Kaliste Formation, the Czech Republic
- France
- Giumal Sandstone Formation, India
- Chia Gara Formation, Iraq
- Sardinia, Italy
- Sabinal Formation and Barril Viejo Shale Member, Mexico
- Myrtle Formation, Oregon, United States
References
{{Reflist|3}}
= Bibliography =
- {{citation |last=Piraquive |first=Alejandro |last2=Díaz |first2=Juan Sebastián |last3=Cuéllar |first3=Tomas |last4=Pardo |first4=Germán |last5=Kammer |first5=Andreas |year=2011 |title=Reactivación Neógena de estructuras de rift del Cretácico Temprano asociadas con la Falla de Chámeza, Pajarito, Boyacá (Colombia): evidencias tectónicas y bioestratigráficas |url=http://www.bdigital.unal.edu.co/24942/1/22167-87412-2-PB.pdf |journal=Geología Colombiana |volume=36 |pages=197–216 |accessdate=2017-08-04}}
External links
- [https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=14510 Acanthodiscus-Paleodb]
- [http://www.ammonites.fr/Fiches/0548.htm Acanthodiscus radiatus] {{Webarchive|url=https://web.archive.org/web/20150413001423/http://www.ammonites.fr/Fiches/0548.htm |date=2015-04-13 }} in French
- T. Birkelund, et al.: Cretaceous Stage Boundaries - Proposals. Bulletin of the Geological Society of Denmark, vol. 33 1984 [http://2dgf.dk/xpdf/bull33-01-02-3-20.pdf]
{{Taxonbar|from=Q2353944}}
Category:Prehistoric cephalopod genera
Category:Fossils of the Czech Republic
Category:Ammonites of North America
Category:Fossils of the United States
Category:Ammonites of South America
Category:Extinct animals of Antarctica
Category:Fossil taxa described in 1792