Lepidotes
| Lepidotes | ||||||||||||
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Fossil of Lepidotes elvensis |
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| Temporal occurrence | ||||||||||||
| Toarcium (Lower Jurassic) | ||||||||||||
| 182.7 to 174.1 million years | ||||||||||||
| Locations | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Lepidotes | ||||||||||||
| Agassiz , 1843 |
Lepidotes is a genus of extinct bony fish thatoccurredin the Toarcian (Lower Jurassic) in Europe. The genus was established in 1843 by the Swiss-American naturalist Louis Agassiz on the basis of two fish species from the Posidonia slate from Ohmden near Stuttgart and subsequently developed into a collective genus (`` wastebasket '' genera) of all possible Mesozoic ray fins , which were often poorly prepared, examined and diagnosed and oftenhave to be classifiedas noun dubium . In January 2012 the genus wasnewly diagnosed by the paleontologist Adriana López-Arbarello , restricted to four species from the Toarcian and newlyassigned tothe Lepisosteiformes (previously Semionotiformes ).
features
Lepidotes species were relatively large fish (> 0.5 m) with a stocky body and an elongated head. Her eyes were small, the teeth pointed with rounded ends. The maxillary (an upper jaw bone) was toothless, very short and wide. The body height was about 35% of the standard length , the head length about 30% of the standard length. The pelvic fins, dorsal and anal fin were located on the rear half of the body, the pelvic fin attachment after about 55% of the standard length, the dorsal fin attachment after about 65% and the anal fin after 75% of the standard length. The dorsal fin was short and pointed, the pelvic fins small, the pectoral fins somewhat larger. The caudal fin was heterocerk and slightly forked. The thick, square ganoid scales arranged in diagonal rows were connected to one another by a joint and could be moved against one another. The square infraorbitalia (bones around the eyes) on the posterior orbit were longer than wide. Numerous suborbitalia (bones below the eye socket) of various shapes and sizes, arranged in rows, covered the sides of the square . Lepidotes only had a pair of extrascapulars (a skull bone). The sideline system extended into the eye region. The middle row of pores lay in a groove between the dermopteroticum (skin bones above the squamosum ) and the parietal bones .
species
- Lepidotes gigas Agassiz, 1832; late Toarcian by Holzmaden (Germany)
- Lepidotes elvensis (Blainville, 1818); Toarcium, France
- Lepidotes semiserratus Agassiz, 1836; Toarcium of Whitby (England),
- Lepidotes bülowianus Jaekel, 1929; Toarcium from Dobbertin , Mecklenburg-Western Pomerania (Germany).
literature
- Adriana López-Arbarello: Phylogenetic Interrelationships of Ginglymodian Fishes (Actinopterygii: Neopterygii). PLoS ONE , doi : 10.1371 / journal.pone.0039370
- Karl Albert Frickhinger: Fossil Atlas of Fishes. Mergus, Verlag für Natur- und Heimtierkunde Baensch, Melle 1999, ISBN 3-88244-018-X .
Web links
- The Paleobiology Database: Lepidotes Agassiz, 1843