Kelmayisaurus

Kelmayisaurus
	Kelmayisaurus jawbone
Temporal occurrence
	Lower Cretaceous (possibly Valanginium to Albium )
	139.3 to 100.5 million years
Locations
	Karamay , Xinjiang Autonomous Region , China;
Systematics
	Lizard dinosaur (Saurischia)
	Theropoda
	Tetanurae
	Allosauroidea
	Carcharodontosauridae
	Kelmayisaurus
Scientific name
	Kelmayisaurus
	Dong , 1973
Art
	Kelmayisaurus petrolicus;

Kelmayisaurus is a genus of theropdan dinosaur of the Carcharodontosauridae familyfrom the Lower Cretaceous China. In 1978, Dong Zhiming published the first scientific description of the genus with the type species K. petrolicus . In 2012, Stephen L. Brusatte, Roger Benson and Xin Xu described him again.

description

In kelmayisaurus there was a large carnivorous dinosaur. A precise size specification is hardly possible due to the scarce fossil material , Brusatte et al. but conclude from the length of the lower jaw that its size was comparable to that of Allosaurus . According to this, Kelmayisaurus reached an estimated length of ten to eleven meters and a weight of about 1600 kg.

The holotype consists of a left lower jaw and parts of the left upper jaw . Only a small fragment of the latter has survived, but shows similarities with the allosauroids Allosaurus , Neovenator and Monolophosaurus . The rough bone surface , as found in more advanced carchadodontosaurids and abelisaurids , is absent. The lower jaw, on the other hand, is well preserved and almost complete. The bone is 525 mm long and has a concave groove on the side , which Brusatte et al. count as autapomorphy .

Systematics

The exact assignment of the genus has long been uncertain. Dong classified Kelmayisaurus in his first description as a megalosaurid , Carroll (1988) saw him as a member of the Carnosauria , Molnar et al. (1990) a tetanure and Dong reclassified it as an allosaurid in 1992 . Rauhut and Xu (2005) finally refer to it as nomen dubium due to the lack of findings .

Brusatte et al. (2011), on the other hand, consider Kelmayisaurus, according to a cladistic analysis, as a valid species and as a basic representative of the Carcharodontosauridae, which, together with Eocarcharia , is compared to the branch of Acrocanthosaurus and other more advanced Carcharodontosaurids.

Carcharodontosauridae

	Eocarcharia

	Kelmayisaurus

	Acrocanthosaurus

	more advanced Carcharodontosauriden (including Carcharodontosaurus , Tyrannotitan )

According to this, Kelmayisaurus would be the second known Carcharodontosaurid from Asia after Shaochilong and thus supports the thesis that this family was widespread during the Lower and Middle Cretaceous Period.

However, the authors also admit that a different classification of Kelmayisaurus cannot be completely ruled out. There is also the possibility of a relationship to, among others, Megalosaurus or Guanlong . A close examination of the fossils and a comparison with other species continue to support the membership of the Carcharodontosauridae.

Individual evidence

↑ ^a ^b Stephen L. Brusatte, Roger BJ Benson, Xing Xu: A reassessment of Kelmayisaurus petrolicus, a large theropod dinosaur from the Early Cretaceous of China. In: Acta Palaeontologica Polonica. Vol. 57, No. 1, 2012, ISSN 0567-7920 , pp. 65-72, doi : 10.4202 / app.2010.0125 .
↑ Zhiming Dong : Dinosaurs from Wuerho. Reports of Paleontological Expedition to Sinkiang (II): Pterosaurian Fauna from Wuerho, Sinkiang. In: Memoirs of the Institute of Vertebrate Paleontology and Paleoanthropology. Vol. 11, 1973, ZDB -ID 1313684-7 , pp. 45-52
^ Robert L. Carroll : Vertebrate Paleontology and Evolution. WH Freeman and Company, New York NY 1988, ISBN 0-7167-1822-7 .
↑ Ralph E. Molnar, Seriozha M. Kurzanov, Zhiming Dong: Carnosauria. In: David B. Weishampel , Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . University of California Press, Berkeley CA et al. 1990, ISBN 0-520-06727-4 , pp. 169-209.
↑ Zhiming Dong: Dinosaurian faunas of China. China Ocean Press et al., Beijing 1992, ISBN 3-540-52084-8 .
↑ Oliver WM Rauhut , Xing Xu : The small theropod dinosaurs Tugulusaurus and Phaedrolosaurus from the Early Cretaceous of Xinjiang, China. In: Journal of Vertebrate Paleontology. Vol. 25, No. 1, 2005, ISSN 0272-4634 , pp. 107-118, doi : 10.1671 / 0272-4634 (2005) 025 [0107: TSTDTA] 2.0.CO; 2 .

[brusatte-1] Stephen L. Brusatte, Roger BJ Benson, Xing Xu: A reassessment of Kelmayisaurus petrolicus, a large theropod dinosaur from the Early Cretaceous of China. In: Acta Palaeontologica Polonica. Vol. 57, No. 1, 2012, ISSN 0567-7920 , pp. 65-72, doi : 10.4202 / app.2010.0125 .

[2] Zhiming Dong : Dinosaurs from Wuerho. Reports of Paleontological Expedition to Sinkiang (II): Pterosaurian Fauna from Wuerho, Sinkiang. In: Memoirs of the Institute of Vertebrate Paleontology and Paleoanthropology. Vol. 11, 1973, ZDB -ID 1313684-7 , pp. 45-52

[3] Robert L. Carroll : Vertebrate Paleontology and Evolution. WH Freeman and Company, New York NY 1988, ISBN 0-7167-1822-7 .

[4] Ralph E. Molnar, Seriozha M. Kurzanov, Zhiming Dong: Carnosauria. In: David B. Weishampel , Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . University of California Press, Berkeley CA et al. 1990, ISBN 0-520-06727-4 , pp. 169-209.

[5] Zhiming Dong: Dinosaurian faunas of China. China Ocean Press et al., Beijing 1992, ISBN 3-540-52084-8 .

[6] Oliver WM Rauhut , Xing Xu : The small theropod dinosaurs Tugulusaurus and Phaedrolosaurus from the Early Cretaceous of Xinjiang, China. In: Journal of Vertebrate Paleontology. Vol. 25, No. 1, 2005, ISSN 0272-4634 , pp. 107-118, doi : 10.1671 / 0272-4634 (2005) 025 [0107: TSTDTA] 2.0.CO; 2 .