Priscacara
| Priscacara | ||||||||||||
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Fossil of Priscacara liops |
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| Temporal occurrence | ||||||||||||
| Eocene | ||||||||||||
| 50 to 45 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Priscacara | ||||||||||||
| Cope , 1877 | ||||||||||||
Priscacara ( Syn . Cockerellites ) was 50 million years ago in the Eocene living harshly related bony fish. It was firstdescribedby Edward Drinker Cope in 1877 . Fossils were found mainly in the Green River Formation in Wyoming , but also on Horsefly Creek in British Columbia .
features
Priscacara was about 15 centimeters long. However, smaller specimens only three centimeters long were found, in exceptional cases specimens longer than 15 centimeters. Priscacara had an oval, often almost round, laterally flattened body. The head was broad, the eyes large. The jaw was short and had small, sharp teeth. The first dorsal fin was supported by spines, the second by branched soft rays. The anal fin was rounded and supported by three spines and branched soft rays. The dorsal fin spines are not round in cross-section, but have a V-shaped notch on the rear side, a feature that is found today in fish with poisonous fin spines.
A distinction is made between two types, Priscacara liops , which had 12 to 13 fin spines in the first dorsal fin and Priscacara serrata , whose slightly shorter first dorsal fin was supported by 9 to 10 fin spines. Priscacara was a freshwater fish and lived in lakes and streams.
Systematics
Priscacara was assigned by some authors to the codfish (Percichthyidae), a family of perch that is no longer found in North America today. Others established the family of Wyoming perches (Priscacaridae) for the genus, or assumed a relationship to the cichlids (Cichlidae). A study from 2010 comes to the conclusion that they can be classified with the sea bass (Moronidae).
literature
- Karl Albert Frickhinger: Fossil Atlas of Fishes. Mergus, Verlag für Natur- und Heimtierkunde Baensch, Melle 1999, ISBN 3-88244-018-X .
- Dorling Kindersley: Encyclopedia of Dinosaurs and Prehistoric Life . 2001, p. 51, ISBN 3-8310-0342-4
- HJ Siber: Green River Fossils. Siber + Siber, AG, 1982
Individual evidence
- ^ Whitlock, JA, 2010. Phylogenetic relationships of the Eocene percomorph fishes Priscacara and Mioplosus. Journal of Vertebrate Paleontology 30 (4): 1037-1048, July 2010 by the Society of Vertebrate Paleontology. PDF
