[D] Kizylkumavis cretacea [~/~]
Describer
Nessov, 1984
Time
Cretaceous Late Turonian Coniacian
Classification
Saurischia Theropoda Tetanurae Coelurosauria Maniraptora Avialae Ornithothoraces Enantiornithes
Fossilsite
Dzharakhuduk locality, Navoi District, Bukhara Province, Outcrop CBI-5a, Bissekt Formation, Uzbekistan
Info
Holotype
TsNIGRI 51/11915, distal fragment of a right humerus.K. cretacea is a very small enantiornithine, the maximum width of the distal end of humerus is 5.1 mm. Originally described as Aves Incertae Sedis. In spite of its fragmantary condition there is no doubt as to the enantiornithine relationships of K. cretacea since it has no fossa for the M. brachialis, a transverse position of the dorsal condyle of the humerus, and an inclined position of the ventral condyle.
Diagnosis
(Nessov, 1984) olecranon fossa is narrow and displaced in the direction of the flexor process; flexor process is strongly projected distally; dorsal condyle verry narrow and aligned at an angle of 65 degrees to the longitudinal axis of the humeral shaft, ans only slightly projected in cranial aspect; intercondylar furrow runs slightly on to cranial site; brachial depression is not developed; a small groove is developed distal to a small ventral supracondylar tubercle on the cranial surface of the distal end, and alligned at an angle of 70 degrees to the longitudinal axis of the shaft.
The following characters form an emended diagnosis for this genus: distal end of the humerus is very wide in the dorsoventral direction; the ventral portion of the distal end of the humerus is remarkably enlarged; the dorsal condyle is broad; the interconylar furrow is narrow; and the flexor process is strongly projected distally.
The humeri of Kizylkumavis and Alexornis of Mexico (Brodkorb, 1976) are similar is some respects. For example, they share: a remarkably distal projection of the ventral epicondyle, distal dispalcement of a shallow olecranal fossa, and an abrupt transmission from the distal end to the shaft. However they also exhibit some differences: the shape of the dorsal condyle (which is broad in Kizylkumavis and narrow and oliveshaped in Alexornis; a more spacious intercondylar furrow in Alexornis, and more distal projection of the flexor process in Kizylkumavis.