Ancolioceras opalinoides (Mayer 1864)

Taxonomy

Ammonite

Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Ammonitida
Family: Graphoceratidae
Genus: Ancolioceras
Species: Ancolioceras opalinoides
Author Citation Mayer 1864

Geological Time Scale

Eon: Phanerozoic
Era: Mesozoic
Period: Jurassic
Sub Period: None
Epoch: Middle
International Age: Late Aalenian

Stratigraphy

Achdorf Formation

Provenance

Collector: Roger Furze
Date Collected: 03/15/2014
Acquired by: Field Collection

Dimensions

Diameter: 9 cm

Location

Scheffheu Section
Wutachtal
Baden-Wuerttemberg
Germany

• a895
• aalenian
• ancolioceras
• germany
• middle jurassic
• murchisonae zone
• opalinoides
• wutachtal

Comments

This species has long been a subject of contention as to its lineage, but Dietze (2014), following the chronospecies/genus concept, has managed to prove to the satisfaction of most that it belongs to the subfamily of the Leioceratinae. Rieber (1963) had placed it in the subfamily Staufeniinae and had named it Staufenia opalinoides, a name which most collectors and paleontologists adopted, since his work was the most comprehensive one on the ammonite fauna of the area for many years.

This almost complete specimen has most of its shell intact. The band of variation of ribbing and other sculptural factors is relatively broad, but this here is a typical sample.

 

Biostratigraphy: Murchisonae Zone, Sinon Bank 1, haugi Subzone

Old German Chronostratigraphy: Dogger (Braunjura) beta

Literature: Rieber,H. (1963): Ammoniten und Stratigraphie des Braunjura beta der Schwaebischen Alb, Palaeontographica Bd.122,Abt.A, Pp.1-89

                   Dietze et al (2014): Aalenian (Middle Jurassic) ammonites and stratigraphy of the Geisingen clay pit (SW Germany), Palaeodiversity 7: 61–127

                   Horn,E. (1909): Die Harpoceraten der Murchisonae-Schichten des Donau-Rhein-Zuges, Mitteilungen der Großh. Badischen Geologischen Landesanstalt, VI. Bd.1.Heft