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| − | <u>Systematic Paleontology</u><br/> |
+ | <u>Systematic Paleontology</u><br /> |
| − | Class [[Cephalopoda]] |
+ | Class [[Cephalopoda]]<br /> |
| − | Subclass [[Nautiloidea]] |
+ | Subclass [[Nautiloidea]]<br /> |
| − | Order [[Discosorida]]<br/> |
+ | Order [[Discosorida]]<br /> |
| − | Family '''Reudemannoceratidae''' |
+ | Family '''Reudemannoceratidae'''<br /> |
The Reudemannoceratidae, which lived during the early Middle Ordovician, is the earliest family of the Discosorida. Named by Rousseau Flower in 1940, the Reudemmanoceratidae are characterized by shells (conchs if you prefer) that are medium to large-sized endogastric cyrtocones and near orthocones with simple apertures bearing a shallow hyponomic sinus. Putting it simply curvature is such that the lower or ventral side is concave (tucked in) in profile; the upper or dorsal side, convex or arched, to nearly straight. Siphuncles are offset slightly from the center, toward the venter. |
The Reudemannoceratidae, which lived during the early Middle Ordovician, is the earliest family of the Discosorida. Named by Rousseau Flower in 1940, the Reudemmanoceratidae are characterized by shells (conchs if you prefer) that are medium to large-sized endogastric cyrtocones and near orthocones with simple apertures bearing a shallow hyponomic sinus. Putting it simply curvature is such that the lower or ventral side is concave (tucked in) in profile; the upper or dorsal side, convex or arched, to nearly straight. Siphuncles are offset slightly from the center, toward the venter. |
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As defined the Reudemannoceratidae includes three genera<br/> |
As defined the Reudemannoceratidae includes three genera<br/> |
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| − | :''[[Reudemannoceras]]''<br/> |
+ | :''[[Reudemannoceras]]''<br/> |
| − | :''[[Franklinoceras]]'' |
+ | :''[[Franklinoceras]]''<br/> |
| − | :''[[Madiganella]]'' |
+ | :''[[Madiganella]]''<br/> |
| − | ''Reudemannoceras'' is considered the source of the Cyrtogomphoceratidae, beginning with ''[[Ulrichoceras]]''; '' |
+ | ''Reudemannoceras'' is considered the source of the Cyrtogomphoceratidae, beginning with ''[[Ulrichoceras]]''; ''Madiganella'' the source of the Mandaloceratidae, beginning with ''[[Pseudogomphoceras]]''. ''Franklinoceras'' seems to have left no descendants. |
| − | <u>References</u><br/> |
+ | <u>References</u><br /> |
| − | Curt Teichert 1964. Nautiloidea - Discosorida. Treatise on Invertebrate Paleontology, Part K |
+ | Curt Teichert 1964. Nautiloidea - Discosorida. Treatise on Invertebrate Paleontology, Part K ''K324 - K326''. |
[[Category:Nautiloids]] |
[[Category:Nautiloids]] |
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[[Category:Ordovician animals]] |
[[Category:Ordovician animals]] |
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Revision as of 20:42, 20 May 2020
Systematic Paleontology
Class Cephalopoda
Subclass Nautiloidea
Order Discosorida
Family Reudemannoceratidae
The Reudemannoceratidae, which lived during the early Middle Ordovician, is the earliest family of the Discosorida. Named by Rousseau Flower in 1940, the Reudemmanoceratidae are characterized by shells (conchs if you prefer) that are medium to large-sized endogastric cyrtocones and near orthocones with simple apertures bearing a shallow hyponomic sinus. Putting it simply curvature is such that the lower or ventral side is concave (tucked in) in profile; the upper or dorsal side, convex or arched, to nearly straight. Siphuncles are offset slightly from the center, toward the venter.
As defined the Reudemannoceratidae includes three genera
Reudemannoceras is considered the source of the Cyrtogomphoceratidae, beginning with Ulrichoceras; Madiganella the source of the Mandaloceratidae, beginning with Pseudogomphoceras. Franklinoceras seems to have left no descendants.
References
Curt Teichert 1964. Nautiloidea - Discosorida. Treatise on Invertebrate Paleontology, Part K K324 - K326.