出典:Wikipedia
出典:『Wikipedia』 (2010/10/12 13:02 UTC 版)
Praeornis is a dubious genus of possible early bird, named on the basis of a single possible feather discovered in the Balabansai Formation of Kazakhstan by Sharov in 1971. In 1978, Rautian officially named the feather (cataloged as specimen PIN 2585/32) Praeornis sharovi. He believed it belonged to a bird more primitive than Archaeopteryx, and assigned it to its own sublcass (Praeornithes), order (Praeornithiformes) and family (Praeornithidae). However, in 1986, Bock published a paper arguing that the "feather" was in fact the leaf of a cycad. This opinion was followed by Doludenko and colleagues in 1990, who noted that it was similar to the leaves of the cycad species Paracycas harrisii. L.A. Nessov, in 1992, also suggested that it belonged to a cycad, but synonymized it with the species Cycadites saportae. The opinion that it represents a leaf has since been followed by Alan Feduccia in 1996 and Peter Wellnhofer in 2004.