Jinfengopteryx elegans

[Tim Williams <twilliams_alpha@hotmail.com>]

Ji Q., Ji S., Lu J., You H., Chen W., Liu Y., and Liu Y. (2005).  First 
avialan bird from China (_Jinfengopteryx elegans_ gen. et sp. nov.)  
Geological Bulletin of China 24(3): 197-205.


_Jinfengopterx_ is called the "first" avialan bird, but the authors really 
seem to mean "most primitive" rather than "earliest".  The specimen (a 
complete skeleton; CAGS-IG-04-0801) comes from the middle of the Qiaotou 
Formation of Hebei Province, which is below the Yixian Formation, but of 
uncertain age (Late Jurassic or Early Cretaceous).  The specimen measures 
54.8 cm long, around half of which is the tail.

The phylogenetic analysis puts _Jinfengopteryx_ as sister taxon to 
_Archaeopteryx_, implying a monophyletic Archaeopterygidae at the base of 
the Avialae (which excludes _Rahonavis_).  The two genera do appear to be 
very similar in overall anatomy.  The authors nevertheless regard 
_Jinfengopteryx_ as more primitive than _Archaeopteryx_, due to its shorter 
rostrum, smaller forelimb/hindlimb ratio, and more cursorial proportions.  
The specimen of _Jinfengopteryx_ appears to be adult (based on skeletal 
fusions), so the more cursorial proportions would not be a product of 
ontogeny as we see in _Archareopteryx_ (if "_Jurapteryx_" is an immature 
specimen of _Archaeopteryx_).

Feather impressions indicate that _Jinfengopteryx_ lacked wings on the legs 
(a la _Microraptor_, _Pedopenna_, etc).  The authors suggest that 
_Jingengopteryx_ supports the cursorial ("ground-up") origin of bird flight, 
but this is a stretch IMHO.

The name is derived from "Jinfeng": "golden phoenix, the queen of birds in 
Chinese folklore".



Tim