Stethacanthidae
| Stethacanthidae | ||||||||||||
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Live reconstruction of Stethacanthus |
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| Temporal occurrence | ||||||||||||
| Upper Devon to Lower Carbon | ||||||||||||
| 382.7 to 323.2 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Stethacanthidae | ||||||||||||
| Lund , 1974 |
The Stethacanthidae are a family of the Symmoriida group within the cartilaginous fish . It was first described by Richard Lund in 1974 and includes the two genera Stethacanthus and Akmonistion . Fossils have been found in North America , Europe and Asia and are dated to the Upper Devonian and Lower Carboniferous .
features
A brush-like extension on the shoulder region is typical of this family. This is covered with teeth on the swollen surface . The appendage consists of a basal plate on the shoulder, a laterally compressed spine in front of it, and the area behind it, which is covered with teeth. The basal plate and the brush made of hollow rods are made of calcified cartilage, the spines are made of trabecular dentine and are surrounded by bone tissue. Teeth have also been found on the roof of the skull, just in front of the process.
Systematics
The Stethacanthidae are only formed by the two genera Stethacanthus and Akmonistion . The closest relative is Falcatus . Both form an unnamed group that is considered to be the sister taxon of the Symmoriidae with the genera Cobelodus , Denaea and Symmorium .
| Symmoriida |
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literature
- Michael J. Benton : Paleontology of the vertebrates. Translation of the 3rd English edition by Hans-Ulrich Pfretzschner. Pfeil, Munich 2007, ISBN 978-3-89937-072-0 .
- Robert L. Carroll : Paleontology and Evolution of the Vertebrates. Thieme, Stuttgart 1993, ISBN 3-13774-401-6 .