Guiyu oneiros
Guiyu oneiros
- Yunnan (China)
Guiyu oneiros is the oldest almost completely preserved fossil fish bone that was found until 2009. The fossil dates from the year-old limestone Kuanti formation near Qujing in the east of Yunnan Province and was dated using index fossils from the group of conodonts at an age of 419 million years.
Etymology
The genus name comes from the Chinese Guiyu (鬼Chinese, Pinyin guǐ = spirit, hidden;鱼Chinese, Pinyin yú = fish). The Style epithet is Greek ( gr όνειρος, oneiros = dream).
Description
The fossil is 26 centimeters long and 11 centimeters high and almost complete, lacking only the tail fin. The head makes up 23% of the body length, the body is 2.5 times as long as high.
Guiyu is a bizarre mix of features previously not bone fishy gnathostomes, meat -finned and Strahlenflossermerkmalen. So he has a primitive pectoral girdle and medium-sized spines, features which also occur in the placoderms, cartilaginous fish and the Acanthodii. With the Fleischflossern he has in common especially numerous features of the skull morphology, as a two-part neurocranium with a movable joint in the middle. It is covered with large, ornamented Rhomboidschuppen. This, as well as the anatomy of the head and the sides Gularknochen ( a bony throat plate ) announces early Strahlenflossern ( Actinopterygii ).
System
Despite an unusual combination of features Guiyu oneiros is considered as basal stem group representatives of the meat -finned fishes. The systematic position shows the following cladogram (after Yu Xiaobo et al (2010). )
Rhipidistia → lungfish ( Dipnoi ) and terrestrial vertebrates ( Tetrapoda )
Styloichthys
Coelacanth ( Coelacanthiformes )
Onychodontiformes
Achoania
Guiyu
Meemannia
Ligulalepis
Swell
- Michael I. Coates: Beyond the Age of Fishes. Nature, Vol 458, March 26, 2009
- Min Zhu, Zhao Wenjin, Liantao Jia, Jing Lu, Tuo Qiao & Qu Qingming: The oldes articulated ostreichyan Reveals mosaic gnathostome characters, Nature, Vol 458, March 26, 2009 doi: 10.1038/nature07855
- Yu Xiaobo, Zhu Min & Zhao Wenjin: The Origin and Diversification of Osteichthyans and Sarcopterygians: Rare Chinese Fossil Findings Advance Research on Key Issues of evolution. Bulletin of the Chinese Academy of Sciences, Paleoichthyology, Vol.24 No.2 2010