Sapeornis

Fossil of Sapeornis chaoyangensis in Hong Kong Science Museum

• Jiufotang lineup, Liaoning (China)

Sapeornis is an ancient bird species that lived about 110-120 million years ago in the Lower Cretaceous ( Aptian - lower Albian upper ). The genus contains ( so far) only the type Sapeornis chaoyangensis documented by fossil finds from the Jiufotang - formation near Chaoyang City, Liaoning Province in the People's Republic of China. It was discovered here more nearly complete skeletons ( Zhou & Zhang 2003).

Etymology

The neologism Sapeornis is derived as follows:

• The abbreviation SAPE for the Society of Avian Paleontology and Evolution,
• From ancient Greek ὄρνις ( ornis ) for " bird " and chaoyangensis as the Latinized adjective to Chaoyang City, so " chaoyangisch ", " from Chaoyang ".

Description

This animal had a life size of about 30-33 cm, the tail feathers (of which there are no findings ) are not included in the calculation. Due to his physique and some notable similarities with species such as the Oviraptorosauria Caudipteryx Sapeornis is usually moved into the relational proximity of Omnivoropteryx ( Czerkas & Ji 2002).

The Hand of Sapeornis was much more developed than in Archaeopteryx. She had three fingers, the two outer fingers each had two, the middle finger three phalanges, the Carpometacarpus was firmly adherent. The arms were one and a half times as long as the legs, suggesting a fairly large wing area. Obviously the structure of the shoulder girdle, but was not particularly suitable for Rüttelflug; also the fork leg was a bit unusual - though it already had the Hypokleidum ( central projection on the leg), and the continued developed bird species, its shape was even more primitive than Archaeopteryx ( Senter 2006). As with the Confuciusornithidae the humerus was big and riddled - probably to save weight.

Only in the maxillary anterior region of the skull had teeth. He is however, there is roughly comparable to the skull structure of Archaeopteryx, with the small Oviraptorosauria and Omnivoropteryx a compelling similarity. Sapeornis also had Gastralia ( bones of the abdominal region) but no or verknorpelte rib extensions ( uncinate process ). A sternum was either absent or only small in size and was therefore easily lost. The pygostyle was rod- like Conficiusornis and Nomingia and how Conficiusornis also Sapeornis had no more tail bone. The Tarsometatarsi were more strongly fused together compared to Archaeopteryx, the fibula was long and reached to the far end of the upper ankle joint - as opposed to the more modern birds (and some non-avian theropods such as Avimimus ). The first toe pointed to the rear. In the found object V12375 of the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences ( IVPP ) of the stomach contained numerous small stomach stones ( gastroliths ).

System

Derived using a number of modern bird features is obvious that p chaoyangensis is about as far from " primitive bird " Archaeopteryx has progressed as Conficiusornis. But his apomorphies are very different from the apomorphies Conficiusornis; so then also shows a study of the characteristics that the two species were not very closely related to each other ( Zhou & Zhang 2006). Since the fletching of Sapeornis is not known so far, nothing can be said about its flow profile. The narrow pygostyle suggests that his tail feathers were only sparsely present as in the Enantiornithes short, or as Conficiusornis. The reduced fingers suggest the presence of a Daumenfittichs. Since Sapeornis was not particularly adapted to the Rüttelflug, it should be probably have been more of a slider and / or sailor who preferred more open landscape areas compared to the Enantiornithes and other forest birds, even though he was quite capable, also on branches settle. Small Gastrolithen, body size and suspected habitat suggest that Sapeornis most likely a herbivore, likely fed on vegetable seeds and fruit. ( Zhou & Zhang 2003)

Swell

• Czerkas, SA & Ji, Q. (2002): A preliminary report on to omnivorous volant bird from northeast China. In: Czerkas, SJ (editor): Feathered Dinosaurs and the Origin of flight. The Dinosaur Museum Journal 1: 127-135. HTML abstract
• Senter, Phil (2006): Scapular orientation in theropods and basal birds, and the origin of flapping flight. Acta Palaeontologica Polonica 51 (2): 305-313. PDF fulltext
• Zhou, Zhonghe & Zhang, Fucheng (2003): Anatomy of the primitive bird from the Early Cretaceous Sapeornis chaoyangensis of Liaoning, China. Canadian Journal of Earth Sciences 40 (5): 731-747. doi: 10.1139/E03-011 (HTML abstract )
• 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 (HTML abstract )