A Comparative Morphological Study of the Jugal and Quadratojugal in Early Birds and Their Dinosaurian Relatives

@article{Wang2017ACM,
  title={A Comparative Morphological Study of the Jugal and Quadratojugal in Early Birds and Their Dinosaurian Relatives},
  author={Min Wang and Han Hu},
  journal={The Anatomical Record},
  year={2017},
  volume={300}
}
  • M. Wang, Han Hu
  • Published 1 January 2017
  • Biology, Medicine
  • The Anatomical Record
The zygoma (called jugal bar) in modern birds accounts for a large portion of the ventral margin of the cranium. As a delicate and rod‐like element, the jugal bar is functionally integrated into the avian cranial kinesis, a unique property that allows the beak to be elevated or depressed with respect to the braincase and thus distinguishes birds from all other modern vertebrates. Developmental studies show that the jugal bar of modern birds is formed by the fusion of the jugal and quadratojugal… Expand
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References

SHOWING 1-10 OF 74 REFERENCES
Discovery of an ornithurine bird and its implication for Early Cretaceous avian radiation.
  • Zhonghe Zhou, Fucheng Zhang
  • Biology, Medicine
  • Proceedings of the National Academy of Sciences of the United States of America
  • 2005
An ornithurine bird, Hongshanornis longicresta gen. et sp. nov., represented by a nearly complete and articulated skeleton in full plumage, has been recovered from the lacustrine deposits of theExpand
Anatomy of the primitive bird Sapeornis chaoyangensis from the Early Cretaceous of Liaoning, China
Two new, nearly completely articulated skeletons of Sapeornis chaoyangensis provide much new information about the anatomy of this basal avian, particularly in the skull, pectoral girdle, forelimb,Expand
Cranial morphology of Archaeopteryx: evidence from the seventh skeleton
TLDR
The avian features of the skull demonstrate that Archaeopteryx is a bird rather than a feathered nonavian archosaur. Expand
A diapsid skull in a new species of the primitive bird Confuciusornis
TLDR
A new species based on a remarkably well preserved skeleton with feathers and, for the first time in the Mesozoic record, direct evidence of the shape of a horny beak is reported, Confuciusornis. Expand
Anatomy of the Basal Ornithuromorph Bird Archaeorhynchus spathula from the Early Cretaceous of Liaoning, China
TLDR
These new specimens are subadult: together with the holotype of Archaeorhynchus, they constitute the entire Early Cretaceous record of subadult ornithuromorphs and reveal important information regarding the ontogeny of this group. Expand
A new small enantiornithine bird from the Jehol Biota, with implications for early evolution of avian skull morphology
TLDR
The results indicate that the quadratojugal is an inverted L-shaped element, morphologically similar to that of more basal birds Archaeopteryx bavarica, Jeholornis prima, Confuciusornis sanctus and Sapeornis chaoyangensis, contributing to the refinement of the cranial kinesis in early birds. Expand
A revision of enantiornithine (Aves: Ornithothoraces) skull morphology
TLDR
A comprehensive overview of the current knowledge of enantiornithine skull anatomy is presented and a number of trophic specializations can be deduced from the range of preserved morphologies, further hinting at the morphological and ecological diversity of the Cretaceous Enantiornithes. Expand
A NEW BASAL BEAKED ORNITHURINE BIRD FROM THE LOWER CRETACEOUS OF WESTERN LIAONING,CHINA
TLDR
A new species of basal ornithurine bird based on a well-preserved specimen from the Lower Cretaceous Jiufotang Formation in Jianchang,western Liao-ning,China that preserves a forked tail composed of elongate rectrices medially separated by a deep notch, which suggests that this tail feather morphology in modern birds decreases aerodynamic efficiency relative to the fan-shaped tail, but increases chance of sexual reproduction. Expand
Cranial morphology of Sinornithosaurus millenii Xu et al. 1999 (Dinosauria: Theropoda: Dromaeosauridae) from the Yixian Formation of Liaoning, China
The recent discovery of the early dromaeosaurid Sinornithosaurus millenii Xu et al. 1999 is especially important for our understanding of maniraptoran evolution, particularly of avian origins. ThisExpand
Jeholornis compared to Archaeopteryx, with a new understanding of the earliest avian evolution
TLDR
The recently reported Jeholornis represents the only known bird with a complete long skeletal tail except for Archaeopteryx, and it is concluded that the common ancestor of birds must have a more primitive tail than that in Archaeoporationx, confirming the side branch position of Archaeoperyx in the early avian evolution. Expand
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4
5
...