Fuente: Nature - Issue - nature.com science feeds
Expuesto el: miércoles, 28 de abril de 2010 18:36
Autor: Xing Xu
Asunto: Exceptional dinosaur fossils show ontogenetic development of early feathers
| Exceptional dinosaur fossils show ontogenetic development of early feathers Nature 464, 1338 (2010). doi:10.1038/nature08965 Authors: Xing Xu, Xiaoting Zheng & Hailu You Recent discoveries of feathered dinosaur specimens have greatly improved our understanding of the origin and early evolution of feathers, but little information is available on the ontogenetic development of early feathers. Here we describe an early-juvenile specimen and a late-juvenile specimen, both referable to the oviraptorosaur Similicaudipteryx, recovered from the Lower Cretaceous Yixian Formation of western Liaoning, China. The two specimens have strikingly different remiges and rectrices, suggesting that a radical morphological change occurred during feather development, as is the case for modern feathers. However, both the remiges and the rectrices are proximally ribbon-like in the younger specimen but fully pennaceous in the older specimen, a pattern not known in any modern bird. In combination with the wide distribution of proximally ribbon-like pennaceous feathers and elongate broad filamentous feathers among extinct theropods, this find suggests that early feathers were developmentally more diverse than modern ones and that some developmental features, and the resultant morphotypes, have been lost in feather evolution. |
