Gogonasus
Gogonasus | ||||||||||||
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Drawing reconstruction of Gogonasus |
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Temporal occurrence | ||||||||||||
Upper Devonian | ||||||||||||
approx. 380 million years | ||||||||||||
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Gogonasus | ||||||||||||
Long , 1985 | ||||||||||||
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Gogonasus is the name of an approximately 380 million year old genus of fossil fish from the late Upper Devonian . Due to their anatomical features and the geological layers in which the fossils were found, Gogonasus is considered an early relative of Panderichthys and Tiktaalik and thus - like them - as the forerunner of the later land vertebrates (tetrapods). A forerunner of Gogonasus was again a fossil fish called Eusthenopteron .
The genus Gogonasus had been known from Western Australia since 1985 . However, the gill regions and the fins, among other things, were poorly preserved in all the finds . It was not until an unusually well-preserved specimen discovered in 2005 in a limestone quarry in the same region (NMV P221897, Museum Victoria, Melbourne ), which even internal organs could be detected with the aid of X-ray analyzes, revealed surprising details: “A mosaic of plesiomorphic and derived Tetrapod-like characteristics. ”In addition to many characteristics typical of fish, Gogonasus - similar to Panderichthys - already had greatly enlarged injection holes (breathing holes) in the area of the gills, from which the auditory canal and middle ear later developed. The arrangement of the pectoral fin bones is similar to that of Tiktaalik , the prehistoric fish that is closest to land vertebrates as far as we know today.
See also
Web links
Individual evidence
- ^ " Gogonasus shows a mosaic of plesiomorphic and derived tetrapod-like features ", quoted from the description of the find: John A. Long, Gavin C. Young, Tim Holland, Tim J. Senden, Erich MG Fitzgerald: An exceptional Devonian fish from Australia sheds light on tetrapod origins. Nature . Volume 444, No. 7116, November 9, 2006, pp. 199-202. doi : 10.1038 / nature05243