The Ancestry of Birds

@article{Ostrom1973TheAO,
  title={The Ancestry of Birds},
  author={John Harold Ostrom},
  journal={Nature},
  year={1973},
  volume={242},
  pages={136-136}
}
WALKER1 has restated the long-held belief that both birds and crocodiles evolved from thecodont ancestors, but he added the novel suggestion that these two groups arose from a common thecodont ancestor and thus are much more closely related than has been previously realized. Inasmuch as the Thecodontia include the most primitive as well as the most ancient archosaurs known, it is highly probable that all subsequent archosaurs (including birds) were derived from members of this order. Although… 
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Feathering and flight evolution in Archaeopteryx
WITH the description of further specimens1,2 there has been a resurgence of interest in Archaeopteryx. Although there is no final agreement on whether it was mainly arboreal or terrestrial, recent
The scapulocoracoid of flightless birds: a primitive avian character similar to that of theropods
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References

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New light on the Origin of Birds and Crocodiles
Detailed evidence from the skull of Sphenosuchus, and from embryological and other resemblances between birds and crocodiles, suggests that these two groups are much more closely related than has
A new specimen of Stenonychosaurus from the Oldman Formation (Cretaceous) of Alberta
A fragmentary skeleton of Stenonychosaurus inequalis indicates that this small theropod dinosaur is very closely related to Saurornithoides mongoliensis from the Cretaceous of central Asia. Both