Gebrayelichthys
| Gebrayelichthys | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| Cenomanium (Middle Cretaceous Period) | ||||||||||||
| 100.5 to 93.9 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Gebrayelichthyidae | ||||||||||||
| Nursall & Capasso , 2004 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Gebrayelichthys | ||||||||||||
| Nursall & Capasso, 2004 | ||||||||||||
Gebrayelichthys is an extinct genus of bony fish from the order of the Pycnodontiformes . Fossils of the genus were found in the plate limestone of the Lebanon Mountains and dated to the Cenomanium (Middle Cretaceous Period). The genus was described on the basis of four type specimens , the photo of a fifth fossil was published as a curiosity in the Spanish branch of the popular science magazine PM Magazins (MUY INTERESANTE). Fossils of the genus are rare. Two species have been described so far , Gebrayelichthys uyenoi and G. vexillarius .
features
Gebrayelichthys was strongly flattened laterally. The body height was 1.8 to 2 times the body length. The head and torso each made up half of the total length. The skull corresponded to that of other Pycnodontiformes. The orbit was located high up under the curved head profile, the snout was long and directed downwards. There were a few pointed teeth on the ploughshare . The anatomy of the lower jaw is unknown due to lack of preservation.
Behind the skull was a tall bone mast that supported a narrow, high ridge. Throughout the fleshy part of the ridge there were fins carrier (Pterygiophoren) a dorsal fin. Immediately behind the lower jaw began a deep, laterally flattened abdominal keel, which was also supported in front by a thick, bony stem and was covered at the sides by bone plates. The belly keel reached as far as the back crest. The trailing edge of the abdominal keel was protected by plate-shaped scales, each with a short, thick spike. Most of the entrails were in the keel of the abdomen. At the front part of the belly keel the flashy lay cloaca . The pelvic fins stood on the leading edge of the keel, the pectoral fins about two thirds of the way up on the keel. A caudal fin is not preserved in any fossil. There is still a notochord in the spine . The scales are small and limited to the body axis and the base of the back crest.
Gebrayelichthys was probably a pelagic fish that ate plankton and small nectonic animals.
literature
- J. Ralph Nursall, Luigi Capasso: Gebrayelichthys (novum), an extraordinary genus of neopterygian fishes from the Cenomanian of Lebanon. In: Gloria Arratia, Andrea Tintori (Ed.): Mesozoic Fishes. Volume 3: Systematics, Paleoenvironments and Biodiversity. Friedrich Pfeil, Munich 2004, ISBN 3-89937-053-8 , 317-340.
- Taverne L. & Capasso L., 2014, Ostéologie et relations phylogénétiques des Gebrayelichtyidae (Halecostomi, Pycnodontomorpha), une extraordinaire famille de poissons du Crétacé supérieur marin du Liban, avec la description d'un nouveau genre. Palaeontos, 25: 44-68.
