Xenacanthus
Xenacanthus Temporal range: Late Devonian–Triassic | |
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Impression of the head and body of Xenacanthus sessilis at the Museum für Naturkunde, Berlin | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Elasmobranchii |
Order: | Xenacanthida |
Family: | Xenacanthidae |
Genus: | Xenacanthus |
Species | |
See text. | |
Synonyms | |
Pleuracanthus |
Xenacanthus is a genus of prehistoric sharks. The first species of the genus lived in the later Devonian period, and they survived until the end of the Triassic, 202 million years ago. Fossils of various species have been found worldwide.
Xenacanthus had a number of features that distinguished it from modern sharks. This freshwater shark was about one meter (three feet) in length.[1] The dorsal fin was ribbon-like and ran the entire length of the back and round the tail, where it joined with the anal fin. This arrangement resembles that of modern conger eels, and Xenacanthus probably swam in a similar manner. A distinctive spine projected from the back of the head, and gives the genus its name. The teeth had an unusual V-shape, and it probably fed on small crustaceans, and heavily scaled palaeoniscid fishes.[2]
As in all fossil sharks, Xenacanthus is mainly known because of fossilised teeth and spines.
Species
- Xenacanthus atriossis
- Xenacanthus compressus
- Xenacanthus decheni
- Xenacanthus denticulatus
- Xenacanthus erectus
- Xenacanthus gibbosus
- Xenacanthus gracilis
- Xenacanthus howsei
- Xenacanthus laevissimus
- Xenacanthus latus
- Xenacanthus luedernesis
- Xenacanthus moorei
- Xenacanthus ossiani
- Xenacanthus ovalis
- Xenacanthus parallelus
- Xenacanthus parvidens
- Xenacanthus robustus
- Xenacanthus serratus
- Xenacanthus slaughteri
- Xenacanthus taylori
References
- ↑ Gaines, Richard M. (2001). Coelophysis. ABDO Publishing Company. p. 17. ISBN 1-57765-488-9.
- ↑ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 27. ISBN 1-84028-152-9.
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