Guiyu oneiros

Guiyu oneiros
	Guiyu oneiros
Temporal occurrence
	Ludlow (late Silurian)
	419 million years
Locations
	Yunnan (China);
Systematics
Trunk :	Chordates (chordata)
Sub-stem :	Vertebrates (vertebrata)
Superclass :	Jaw mouths (Gnathostomata)
Class :	Meat finisher (Sarcopterygii)
Genre :	Guiyu
Type :	Guiyu oneiros
Scientific name of the genus
	Guiyu
	Zhu et al. , 2009
Scientific name of the species
	Guiyu oneiros
	Zhu et al., 2009

Guiyu oneiros is the oldest, almost completely preserved fossil bony fish that was found until 2009. The fossil comes from year-old limestone of the Kuanti Formation near Qujing in the east of the Chinese province of Yunnan and wasdated to an age of 419 million yearswith the help of key fossils from the group of Conodonts .

etymology

The generic name Guiyu comes from Chinese ( Chinese 鬼 , Pinyin guǐ = spirit, hidden; Chinese 鱼 , Pinyin yú = fish). The type epithet is Greek (Greek όνειρος , óneiros = dream).

description

The fossil is 26 centimeters long and 11 centimeters high and almost complete, only the caudal fin is missing. The head makes up 23% of the body's length, the body is 2.5 times as long as it is high.

Guiyu shows a bizarre mixture of characteristics of early, non-bonefish jaw mouths , of meat-fin and ray - fin characteristics . It has a primitive shoulder girdle and medium-sized fin spines, features that also occur in the placodermi , cartilaginous fish and the acanthodii . Above all, it has numerous features of the skull morphology in common with the meat fins, such as a two-part neurocranium with a movable joint in the middle. It is covered with large, ornamented rhomboid scales. This, as well as the anatomy of the head sides and the gular bones (a bony throat plate) shares with early ray fins (Actinopterygii).

Systematics

Despite an unusual mixture of characteristics, Guiyu oneiros is considered to be the basic core group representative of the meat finisher. The systematic position shows the following cladogram (according to Yu et al. (2010)):

Sarcopterygii

Sarcopterygii- crown group

	Rhipidistia , including lungfish (Dipnoi) and terrestrial vertebrates (Tetrapoda)

	† Styloichthys

Actinistia

	Quastenflosser (Coelacanthiformes)

	† Eoactinistia

† Onychodontiformes

	† Achoania

	† Psarolepis

† Guiyu

† Meemannia ^*

† Ligulalepis ^*

^*According to recent findings is Meemannia the geologically oldest ray-finned and Lingualepis a core group representatives of bonefish .

swell

Michael I. Coates: Beyond the Age of Fishes . Nature, Vol 458, March 26, 2009
Min Zhu, Wenjin Zhao, Liantao Jia, Jing Lu, Tuo Qiao & Qingming Qu: The oldes articulated osteichthyan 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

Web links

Palaeoblog Guiyu : The Oldest Articulated Osteichthyan
ScienceBlogs Guiyu oneiros

Individual evidence

↑ Jing Lu, Sam Giles, Matt Friedman, Jan L. den Blaauwen, Min Zhu: The Oldest Actinopterygian Highlights the Cryptic Early History of the Hyperdiverse Ray-Finned Fishes. Current Biology, 2016, in press, doi: 10.1016 / j.cub.2016.04.045 ( Open Access )

[1] Jing Lu, Sam Giles, Matt Friedman, Jan L. den Blaauwen, Min Zhu: The Oldest Actinopterygian Highlights the Cryptic Early History of the Hyperdiverse Ray-Finned Fishes. Current Biology, 2016, in press, doi: 10.1016 / j.cub.2016.04.045 ( Open Access )