Sapeornis
| Sapeornis | ||||||||||||
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Sapeornis chaoyangensis fossil in the Hong Kong Science Museum |
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| Temporal occurrence | ||||||||||||
| Lower Cretaceous ( Aptium ) | ||||||||||||
| 126.3 to 112.9 million years | ||||||||||||
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| Scientific name | ||||||||||||
| Sapeornis | ||||||||||||
| ZH Zhou & FC Zhang , 2002 | ||||||||||||
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Sapeornis is a primitive bird - species that before about 110 to 120 million years ago in the Cretaceous ( upper Aptian - Lower Albian ) lived. The genus (so far) only contains the species Sapeornis chaoyangensis , documented by fossil finds from the Jiufotang formation near the city of Chaoyang , Liaoning Province in the People's Republic of China . Several almost complete skeletons were discovered here (Zhou & Zhang 2003).
etymology
The word creation Sapeornis is derived as follows:
- the abbreviation SAPE for S ociety of A vian P aleontology and E volution [1] ,
- from the ancient Greek ὄρνις (ornis) for "bird" and chaoyangensis as the Latinized adjective for the city of Chaoyang, ie "chaoyangisch", "from Chaoyang".
description
This animal had a life size of approx. 30–33 cm, not including the tail feathers (of which there are no findings). Due to its physique and some remarkable similarities with species of the Oviraptorosauria such as z. B. Caudipteryx , Sapeornis is usually brought into the family proximity of Omnivoropteryx (Czerkas & Ji 2002).
The Sapeornis hand was much more developed than that of Archeopteryx . She had three fingers, the two outer fingers each had two, the middle finger three phalanges , the carpometacarpus was firmly fused. The arms were one and a half times as long as the legs, which suggests a fairly large wing area. Obviously the construction of the shoulder girdle was not particularly suitable for the jolt flight; The wishbone was also somewhat unusual - although it already had the hypocleidum (central process on the wishbone) of the more advanced bird species, its shape was even more primitive than that of Archeopteryx (Senter 2006). As with the Confuciusornithidae , the humerus was large and perforated - probably to save weight.
The skull only had teeth in the anterior maxilla. It is roughly comparable to the skull structure of the Archeopteryx , but there is a striking resemblance to the small Oviraptorosauria and Omnivoropteryx . Sapeornis also had gastralia (bones of the abdominal region) but no or only cartilaginous costal processes ( uncinate process ). One sternum was either absent or small and therefore easily lost. The pygostyle was like Confuciusornis and nomingia rod-shaped and as Confuciusornis also had sapeornis no tail bone more. The Tarsometatarsi were compared with Archeopteryx significantly grown stronger together, the fibula was long and reached to the far end of the ankle - as opposed to the more modern birds (and some non-avian theropods such as. Avimimus ). The first toe pointed backwards. In find V12375 of the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences (IVPP), the stomach contained numerous small stomach stones (gastroliths).
Systematics
Using a number of modern bird characteristics, it becomes apparent that S. chaoyangensis evolved about as far from the "primordial bird" Archeopteryx as Confuciusornis . His apomorphies , however, differ very strongly from the apomorphies of Confuciusornis ; an examination of the characteristic features shows that the two species were not very closely related to each other (Zhou & Zhang 2006). Since the fletching of Sapeornis is not yet known, nothing can be said about its flow profile. The narrow pygostyle indicates that its tail feathers were short, as in the Enantiornithes , or only sparsely , as in Confuciusornis . The reduced fingers suggest the presence of a thumb wing . Since Sapeornis was not particularly adapted to the jolting flight, he was probably more of a glider and / or sailor who, compared to the enantiornithes and other forest birds, preferred more open landscapes, even if he was quite able to stand on branches settle down. Small gastroliths, body size and assumed habitat suggest that sapeornis was most likely a herbivore that was likely to have fed on plant seeds and fruits (Zhou & Zhang 2003)
swell
- Czerkas, SA & Ji, Q. (2002): A preliminary report on an omnivorous volant bird from northeast China. In: Czerkas, SJ (editor): Feathered Dinosaurs and the origin of flight. The Dinosaur Museum Journal 1: 127-135.
- Senter, Phil (2006): Scapular orientation in theropods and basal birds, and the origin of flapping flight. Acta Palaeontologica Polonica 51 (2): 305-313. PDF
- Zhou, Zhonghe & Zhang, Fucheng (2003): Anatomy of the primitive bird Sapeornis chaoyangensis from the Early Cretaceous of Liaoning, China. Canadian Journal of Earth Sciences 40 (5): 731-747. doi : 10.1139 / E03-011
- Zhou, Zhonghe & Zhang, Fucheng (2006): A beaked basal ornithurine bird (Aves, Ornithurae) from the Lower Cretaceous of China. Zool. Scripta 35: 363-373. doi : 10.1111 / j.1463-6409.2006.00234.x
