Rhynchonellida
| Rhynchonellida | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Stegerhynchus borealis (from Buch, 1834) |
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| Temporal occurrence | ||||||||||||
| Ordovician to recent | ||||||||||||
| 488 to 0 million years | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Rhynchonellida | ||||||||||||
| Kuhn , 1949 |
Rhynchonellida (Rhynchonellida) are a taxon of arm pods (Brachiopoda) with a short lock rim, with a more or less spherical housing and an impunctate shell. Simple arm rests (crurs) are approaches to the fleshy arm structure. Together with the Protorthida , Orthida , Spiriferida , Atrypida , Pentamerida and Terebratulida , they form the taxon Rhynchonellata , which in turn belongs to the sub-strain of the Rhynchonelliformea .
features
The short beak of the ventral valve or stem valve ("rostrat") and the appearance of sinuses and bulges are characteristic. The delthyrium is narrowed on both sides by deltidial plates . The representatives of the Rhynchonelliden are very similar externally. The construction of crura and septa is important for the taxonomic classification (serial cuts required).
Systematics
The rhynchonellids are divided into two sub-taxa, which are subdivided according to the formation of a spondylium:
- Rhynchonellacea without spondylium (Ordovician until today)
- Stenocismatacea with Spondylium (Devonian to Permian)
literature
- Bernhard Ziegler: Introduction to Paleobiology Part 3 . ISBN 3-510-65179-0
- Treatise of Invertebrate Paleontology: H (Brachiopoda revised) 2 . ISBN 0-8137-3108-9
- Ulrich Lehmann, Gero Hillmer: Invertebrates of the past . ISBN 3-432-90653-6
Individual evidence
- ^ O. Kuhn: Textbook of Palaeozoology. 326 S., E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, 1949
