Stethacanthus
| Stethacanthus | ||||||||||||
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Male and female of the Middle Paleozoic Elasmobranch Stethacanthus altonensis as a living reconstruction. |
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| Temporal occurrence | ||||||||||||
| Upper Devonian to Lower Carboniferous | ||||||||||||
| 370 to 345 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Stethacanthus | ||||||||||||
| Newberry , 1889 |
Stethacanthus ("breast sting") is a genus of shark-like cartilaginous fish that lived in the Upper Devonian and Lower Carboniferous (370 to 345 million years ago) and whose remains have been found in North America, Europe and northern Asia. Six species have so far been scientifically described .
Description and way of life
The size of the animal usually stayed under one meter, but specimens up to two meters long have also been found. The most striking feature of Stethacanthus was an anvil-shaped anterior dorsal fin made of calcitic cartilage , which was only developed in the male ( sexual dimorphism ). On top it was covered with small spines from enlarged placoid scales , which could also be found on the head. It is believed that this structure served as a deterrent and defense against enemies or rivals and had a function in finding a partner. Apart from the spiky scales on the dorsal fin and head, Stethacanthus had no scales.
The animal's pectoral fin improved stability and, together with the well-balanced tail fin, made the fish an agile hunter. Stethacanthus probably primarily hunted small fish and other marine animals.
species
The following species are assigned to the genus Stethacanthus :
- S. altonensis St John & Worthen, 1875
- S. mirabilis Agassiz, 1843
- S. praecursor Hossakof & Bryant, 1918
- S. productus Lund & Zangerl, 1974
- S. thomasi Turner, 1982
- S. gansuensis Wang, Jin & Wang, 2004
literature
- Richard Lund: Stethacanthid elasmobranch remains from the Bear Gulch Limestone of Montana . 1985
- Haines, Chambers: The Complete Guide to Prehistoric Life . 2006
Web links
- MI Coates, SEK Sequeira, IJ Sansom, MM Smith (1998): Spines and tissues of ancient sharks . In: Nature 396, December 24, 1998, pp. 729-730 DOI: 10.1038 / 25467 . Illustration with legend
Individual evidence
- ↑ Mikko's Phylogeny Archive: † Symmorida ( Memento of the original from February 3, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. simplified
