Sinopterus
| Sinopterus | ||||||||||
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Sinopterus dongi fossil . |
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| Temporal occurrence | ||||||||||
| Lower Cretaceous ( Aptium ) | ||||||||||
| 126.3 to 112.9 million years | ||||||||||
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Sinopterus | ||||||||||
| Wang & Zhou , 2003 | ||||||||||
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Sinopterus is a genus of short-tailed pterodactic dinosaurs (Pterodactyloidea) from the group of Tapejaridae . Fossils come from the Lower Cretaceous ( Aptian ) of the Jiufotang Formation ( Jehol Group ) in China . So far, three types have been described, two of which are currently considered valid.
features
Sinopterus was a medium-sized short-tailed pterosaur . The holotype specimen of Sinopterus dongi had a wingspan of 1.18 meters, while another, larger specimen of this species (specimen number D 2525) had a wingspan of about 2 meters. A third specimen, formerly known as Sinopterus gui , representing a very young individual, showed a wingspan of 0.64 meters. The holotype specimen of the second species, Sinopterus jii , is estimated to have a wingspan of 1.62 meters.
The skull was relatively long and low and measures 17 centimeters in the holotype specimen. It ended in a slender, toothless muzzle with a horn beak. Sinopterus differs from other representatives of the Tapejaridae in the shape of the cranial crest , which was less pronounced in the front section, but curved upwards in the rear section. In addition, the nasoantorbital window, the skull window in front of the eyes , was smaller than in other Tapejaridae. The downward ridge of the lower jaw was flatter than in related genera.
Research history and species
Sinopterus was first scientifically described in 2003 with the species Sinopterus dongi by Wang and Zhou . This description is based on a relatively complete skeleton including skull. It was the first record of a representative of the Tapejaridae outside of Brazil.
A second species, " Sinopterus gui ", which is now considered invalid , was set up in 2003 by Li, Lü and Zhang. These researchers distinguished the new species by the presence of a notary , the absence of a skull crest and a comparatively smaller thigh bone. However, Kellner and Campos (2007) show that there was no notary and that the length of the femur was incorrectly measured. Rather, according to these researchers, it was a very young specimen of Sinopterus dongi .
A third species, Sinopterus jii , was assigned to this genus by Wang and Zhou (2007). Kellner and Campos (2007) confirm this assignment. This species was originally described by Lü and Yuan (2005) under the name " Huaxiapterus jii " as a type species of the genus Huaxiapterus .
Individual evidence
- ↑ a b c d e Alexander WA Kellner, Diogenes A. Campos: Short note on the ingroup relationships of the Tapejaridae (Pterosauria, Pterodactyloidea). In: Boletim do Museu Nacional do Rio de Janeiro. Geologia. Vol. 75, 2007, ISSN 0080-3200 , pp. 1-14.
- ↑ Junchang Lü, Jinyuan Liu, Xuri Wang, Chunling Gao, Qingjin Meng, Qiang Ji: New Material of Pterosaur Sinopterus (Reptilia: Pterosauria) from the Early Cretaceous Jiufotang Formation, Western Liaoning, China. In: Acta Geologica Sinica. English edition. Vol. 80, No. 6, 2006, ISSN 1000-9515 , pp. 783-789, doi : 10.1111 / j.1755-6724.2006.tb00302.x .
- ↑ a b c Xiaolin Wang, Zhonghe Zhou : A new pterosaur (Pterodactyloidea, Tapejaridae) from the Early Cretaceous Jiufotang Formation of western Liaoning, China and its implications for biostratigraphy. In: Chinese Science Bulletin. Vol. 48, No. 1, 2003, ISSN 1001-6538 , pp. 16-23, doi : 10.1007 / BF03183326 .
- ↑ Jianjun Li, Junchang Lu, Baokun Zhang: A new Lower Cretaceous sinopterid pterosaur from the Western Liaoning, China. In: Acta Palaeontologica Sinica. Vol. 42, No. 3, 2003, ISSN 0001-6616 , pp. 442-447.
