A precocial avian embryo from the Lower Cretaceous of China.
An embryo of an enantiornithine bird has been recovered from the Lower Cretaceous rocks of Liaoning, in northeast China. The bird has a nearly complete articulated skeleton with feather sheet impressions and is enclosed in egg-shaped confines. The tucking posture of the skeleton suggests that the embryo had attained the final stage of development. The presence of well-developed wing and tail feather sheets indicates a precocial developmental mode, supporting the hypothesis that precocial birds appeared before altricial birds.
Zhou
Zhonghe
Z
Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Post Office Box 643, Beijing 100044, China. zhonghe@yeah.net
Zhang
Fucheng
F
D000818:Animals; D001717:Birds / Q000196:embryology*; D002681:China; D004625:Embryo, Nonmammalian / Q000033:anatomy & histology*; D005241:Feathers / Q000196:embryology; D005580:Fossils; D014921:Wings, Animal / Q000196:embryology