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Jeholornis - long-tailed bird in today's Nature



 

Z. Zhou and F. Zhang (2002) A long-tailed, seed-eating bird from the Early
Cretaceous of China.  Nature 418: 405-409.  

"The lacustrine deposits of the Yixian and Jiufotang Formations in the Early
Cretaceous Jehol Group in the western Liaoning area of northeast China are
well known for preserving feathered dinosaurs, primitive birds and mammals.
Here we report a large basal bird, _Jeholornis prima_ gen. et sp. nov., from
the Jiufotang Formation.  This bird is distinctively different from other
known birds of the Early Cretaceous period in retaining a long skeletal tail
with unexpected elongated prezygopophyses and chevrons, resembling that of
dromaeosaurids, providing a further link between birds and non-avian
theropods.  Despite its basal position in early avian evolution, the
advanced features of the pectoral girdle and the carpal trochlea of the
carpometacarpus of _Jeholornis_ indicate the capability of powerful flight.
The dozens of beautifully preserved ovules of unknown plant taxa in the
stomach represents direct evidence for seed-eating adaptation in birds of
the Mesozoic era."

Holotype. IVPP (Institute of Vertebrate Paleontology and Paleoanthropology,
Beijing, China) collection number V13274, a nearly completely articulated
skeleton.  The authors believe there is no chance that the specimen is a
composite.



That's right - a bird with a long dromaeosaurid-like tail, complete with
elongated and rod-like prezygapophyses and chevrons.  _Jeholornis_ also has
a T-shaped lacrimal; toothless upper jaw with a few teeth in the lower jaw
(these are small and conical); short sternum; robust boomerang-like furcula;
a forelimb to hindlimb ratio of about 1.2; three large and recurved unguals
on the hand; a reversed hallux; pedal claws consistent with perching; and a
large claw on the second toe "reminiscent of the situation of dromaeosaurids
and troodontids".  

Strangely enough, no feathers were preserved.  The authors are certain
_Jeholornis_ could fly: "The derived features of the pectoral girdle of
_Jeholornis_ such as a strut-like coracoid and the well-developed carpal
trochlea of the carpometacarpus, suggest the capability of powerful flight."


_Jeholornis_ is a big bird - larger than _Archaeopteryx_ but smaller than
_Sapeornis_.

Seeds (ovules) were found in the abdominal cavity, corresponding to the
location of the stomach.  The authors aver that _Jeholornis_ could have fed
on seeds on the ground, or picked them out of cones on the trees, or both.

Last rites for BAND?  



Tim


------------------------------------------------------------------- 



Timothy J. Williams, Ph.D. 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 (office) 
Fax:   515 294 9359