Confuciusornis
sanctus
Confuciusornis sanctus Hou et al., 1995 is a famous fossil bird from
China. Many skeletons with preserved feathers have been found in the
Jehol Lagerstätte, an Early Cretaceous lake deposit in North China having an
abundance of well-preserved fossils, many with nonmineralizing parts still
present. The most spectacular fossils in the Jehol Lagerstätte have been
feathered dinosaurs and early birds. The lake deposits are rich in
volcanic sediments, and the macrovertebrates have been interpreted to have been
killed and buried by volcanic ash.
Confuciusornis has asymmetrical flight feathers and lacks teeth in
its mouth, so it is considered the oldest known beaked bird. The
Jurassic-aged fossil bird Archaeopteryx,
from the Solnhofen Limestone of Germany, does have teeth. Unlike modern
birds, Confuciusornis has three clawed fingers on the leading edge of
each wing. Hundreds of specimens have been found, often in close
proximity on bedding planes. These mass mortality beds consistent with
the volcanic ash burial model that accounts for the exquisite preservation of
Jehol fossils. Confuciusornis fossils frequently have well
preserved wing, tail, body, and neck feathers. Some Confuciusornis
specimens have exceedingly long tail feathers. Such long-tailed fossils
are often found in close proximity to individuals having very short tail
feathers. The Chinese have concluded that this may be evidence for sexual
dimorphism in the species, and the long-tailed individuals are inferred to be
males.
Classification: Animalia, Chordata, Vertebrata, Aves,
Confuciusornithiformes, Confuciusornithidae
Stratigraphy: 3rd unit of the Yixian Formation (sensu Fürsich et al., 2007)
(a.k.a. Jianshangou Unit; a.k.a. Jianshangou Bed; a.k.a.
Chaomidianzi Formation), Jehol Group, Lower Cretaceous (an upper Upper Jurassic
assignment was initially preferred by Chinese researchers, but available
information indicates an Early Cretaceous age).
Locality:
Sihetun Quarry, Liaoning Province, northeastern China
Confuciusornis sanctus Hou et al., 1995 (above & below) from the Lower
Cretaceous of Liaoning, China - the most distinctive skeletal feature is the
presence of a large hole (fenestra) near the proximal end of the humerus of
each arm (see labeled photo below).
(Walter L. Gross III collection, public display, Cincinnati
Museum of Natural History and Science, Cincinnati, Ohio, USA)
Confuciusornis sanctus Hou et al., 1995 from the Lower Cretaceous of
Liaoning, China - closeup of skull.
Confuciusornis sanctus Hou et al., 1995 from the Lower Cretaceous of
Liaoning, China - closeup of posterior of specimen shown above, showing clawed
feet and well-preserved feathers.
Mostly synthesized from:
Wu et al. (2002) - Fossil Treasures from Liaoning.
Beijing. Geological Publishing House. 138 pp. [in Chinese &
English]
Chang et al. (2003) - The Jehol Biota.
Shanghai. Shanghai Scientific & Technical Publishers. 209 pp.
Chen et al. (2005) - Jianshangou Bed of the Yixian
Formation in West Liaoning, China. Science in China, Series D, Earth
Sciences 48: 298-312.
Fürsich et al. (2007) - High resolution
palaeoecological and taphonomic analysis of Early Cretaceous lake biota,
western Liaoning (NE-China). Palaeogeography, Palaeoclimatology,
Palaeoecology 253: 434-457.