Megalichthyidae
| Megalichthyidae | ||||||||||||
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Ectosteorhachis , reconstruction drawing |
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| Temporal occurrence | ||||||||||||
| Middle Devon to Unterperm | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Megalichthyidae | ||||||||||||
| Hay , 1902 |
The Megalichthyidae are an extinct family of the meat fins (Sarcopterygii), which occurred from the Upper Devonian to the Lower Permian.
features
Synapomorphies that diagnose the taxon are the elongated or slit-shaped outer nostrils that are partially enclosed at the back by a bone. The outgrowth of the intermediate jaws (premaxillary) lying behind between the maxillaria has tusks. The ploughshare (vomer) is short and wide and sometimes has a strong mesial outgrowth. The tear bone (lacrimale) has a well developed notch. The parietal bone is notched to enclose the posterior nasal bone . The latter characteristic is not generally accepted because it is of variable expression.
Genera
- Cladarosymblema (Unterkarbon, Fox, Campbell, Barwick & Long, 1995)
- Ectosteorhachis (Carbon to Unterperm, Cope, 1880)
- Lohsania (Lower Permian Utah, Thomson & Vaughn, 1968)
- Mahalalepis ? (Central Devon of Antarctica, Young et al., 1992)
- Megalichthys (Carbon to Unterperm, Agassiz, 1835)
- Megapomus (Central Devon of Russia, Vorobyeva, 1977)
- Megistolepis (Upper Devonian Siberia, Obruchev, 1955)
- Palatinichthys (Unterperm von Germany, Witzmann et al., 2012)
- Sengoerichthys (Upper Devonian Turkey, Janvier et al., 2007)
Systematics
The Megalichthyidae were previously placed in the order Osteolepiformes , which is now considered paraphyletic . Today they form together with the genera gogonasus , Gyroptychius , Medoevia and Osteolepis order Megalichthyiformes , the sister group of eotetrapodiformes is, from the finally land vertebrates emerged (Tetrapoda).
The systematic position shows the following cladogram:
| Tetrapodomorpha |
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literature
- Philippe Janvier, Gaël Clément, Richard Cloutier: A primitive megalichthyid fish (Sarcopterygii, Tetrapodomorpha) from the Upper Devonian of Turkey and its biogeographical implications. Geodiversitas 29 (2): 249-268.
Individual evidence
- ↑ Florian Witzmann, Rainer R. Schoch (2012): A megalichthyid sarcopterygian fish from the Lower Permian (Autunian) of the Saar-Nahe Basin, Germany. Geobios doi : 10.1016 / j.geobios.2011.03.002
- ^ Brian Swartz: A Marine Stem-Tetrapod from the Devonian of Western North America. PLoS doi : 10.1371 / journal.pone.0033683
Web links
- Palaeos: Megalichthyidae