Scanilepiformes

Scanilepiformes
Temporal occurrence
	Triad
	251.9 to 201.3 million years
Locations
	Asia (China, Siberia, Kyrgyzstan); North America (USA); Europe (Sweden);
Systematics
Over trunk :	Neumünder (Deuterostomia)
Trunk :	Chordates (chordata)
Sub-stem :	Vertebrates (vertebrata)
Superclass :	Jaw mouths (Gnathostomata)
Class :	Ray fins (Actinopterygii)
Order :	Scanilepiformes
Scientific name
	Scanilepiformes
	Sytchevskaya , 1999

The Scanilepiformes are an extinct bony fish order from the class of the ray fins (Actinopterygii). Fossils of the group, mainly derived from non-marine Triassic deposits , have been found in Asia, North America and Sweden.

features

Scanilepiformes had an elongated, spindle-shaped body and a blunt snout; they reached standard lengths of 10 cm ( Fukangichthys ) to 1.25 m ( Scanilepis ). Its long dorsal fin, supported by 51 ( Fukangichthys ) to 150 ( Scanilepis ) rays, is striking . The rear edge of the dorsal and anal fin was rounded, the caudal fin rounded or straight. The tail stalk was short. The number of suborbitalia (bones below the eye socket) was two to four, those of the Branchiostegal rays on each side between 6 ( Evenkia ) and 10 ( Tanaocrossus ).

Systematics

Before the establishment of the order by Sytchevskaya in 1999, the genera of the Scanilepiformes were assigned to the Palaeonisciformes , Cheirolepiformes or Perleidiformes . The systematic position of the Scanilepiformes is controversial. Guang-Hui Xu et al. Place them in the core group of the Neopterygii , while Giles and colleagues classified them as the sister group of the pike-pike (Polypteridae) in a study published in 2017 .

The simplified cladogram shows the two alternatives of the systematic position of the Scanilepiformes within the ray fins (Actinopterygii):

Actinopterygii

Actinopteri

Neopterygii

	Real bony fish (Teleostei)

	Bone organoids (holostei)

† Platysomiformes

† Scanilepiformes according to Guang-Hui Xu et al.

Cartilage organoids (chondrostei)

† Rhadinichthyidae

	† Scanilepiformes according to Giles et al.

	Flösselhechte (Polypteriformes)

† Cheirolepis

Genera

Beishanichthys Xu & Gao, 2011, Lower Triassic, Bejschan (China)

Fukangichthys Su, 1978, Central Triassic, Xinjiang (China)

Evenkia Berg, 1941, Upper Triassic, Siberia

Mizhilepis , Upper Triassic, Shaanxi (China)

Oshia Sytchevskaya, 1999, Upper Triassic, Kyrgyzstan

Scanilepis Aldinger, 1935, Upper Triassic, Sweden

Tanaocrossus Schaeffer, 1967, Upper Triassic, USA

literature

Guang-Hui Xu, Ke-Qin Gao & John A. Finarelli: A Revision of the Middle Triassic Scanilepiform Fish Fukangichthys longidorsalis from Xinjiang, China, with Comments on the Phylogeny of the Actinopteri. Journal of Vertebrate Paleontology, 34 (4): 747-759. 2014. doi: 10.1080 / 02724634.2014.837053
Sytchevskaya, EK 1999. Freshwater fish fauna from the Triassic of Northern Asia. In: G. Arratia & H.-P. Schultze (Ed.), Mesozoic Fishes 2: Systematics and Fossil Record. Publishing house Dr. Friedrich Pfeil, Munich.

Individual evidence

↑ ^a ^b Sam Giles, Guang-Hui Xu, Thomas J. Near, Matt Friedman. Early members of 'living fossil' lineage imply later origin of modern ray-finned fishes. Nature , 2017; DOI: 10.1038 / nature23654

[Giles-1] Sam Giles, Guang-Hui Xu, Thomas J. Near, Matt Friedman. Early members of 'living fossil' lineage imply later origin of modern ray-finned fishes. Nature , 2017; DOI: 10.1038 / nature23654