Another enantiornithean wing from China

[Tim Williams <twilliams_alpha@hotmail.com>]

Apologies in advance if this has been mentioned already...

Jerald D. Harris, Matthew C. Lamanna, Hai-lu You, Shu-an Ji, and Qiang Ji  
(2006).  A second enantiornithean (Aves: Ornithothoraces) wing from the 
Early Cretaceous Xiagou Formation near Changma, Gansu Province, People's 
Republic of China.  Can. J. Earth Sci. 43 (5): 547-554.

Abstract: "A new specimen of an enantiornithean bird from the Lower 
Cretaceous Xiagou Formation of Gansu Province, northwestern China, consists 
of an articulated distal left humerus, ulna, radius, carpus, and manus. The 
specimen may represent a primitive enantiornithean because it lacks a 
longitudinal sulcus on the radius, has incompletely fused alular and major 
metacarpals, and possibly retains a remnant of a second phalanx on the minor 
digit. It differs from all other known enantiornitheans, and exhibits 
possible autapomorphies, including peculiar, flat humeral epicondyles, a 
pair of eminences on the distal minor metacarpal, and an enormous flexor 
tuberculum on the alular ungual. The specimen probably pertains to the same 
taxon as a previously described enantiornithean arm from Changma; the 
incompleteness of the taxon precludes erecting a new name, but it provides 
new information concerning enantiornithean diversity in the Early Cretaceous 
of central Asia."