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New paper on pre-Archaeopteryx coelurosaurian dinosaurs



From: Ben Creisler
bh480@scn.org

In case this new paper has not been mentioned:

Xing Xu, QingYu Ma and DongYu Hu (2010)
Pre-Archaeopteryx coelurosaurian dinosaurs and their 
implications for understanding avian origins. 
Chinese Science Bulletin (advance online publication)
DOI: 10.1007/s11434-010-4150-z

The last two decades have witnessed great advances in 
reconstructing the transition from non-avian theropods to 
avians, but views in opposition to the theropod 
hypothesis still exist. Here we highlight one issue that 
is often considered to raise problems for the theropod 
hypothesis of avian origins, i.e. the ?temporal paradox? 
in the stratigraphic distribution of theropod fossils ? 
the idea that the earliest known avian is from the Late 
Jurassic but most other coelurosaurian groups are poorly 
known in the Jurassic, implying that avians arose before 
their supposed ancestors. However, a number of Jurassic 
non-avian coelurosaurian theropods have recently been 
discovered, thus documenting the presence of most of the 
major coelurosaurian groups in the Jurassic alongside, or 
prior to, avians. These discoveries have greatly improved 
the congruence between stratigraphy and phylogeny for 
derived theropods and, effectively, they reject 
the ?temporal paradox? concept. Most importantly, these 
discoveries provide significant new information that 
supports the relatively basal positions of the 
Tyrannosauroidea and Alvarezsauroidea among the 
Coelurosauria. Indeed, they imply a new phylogenetic 
hypothesis for the interrelationships of Paraves, in 
which Archaeopteryx, the Dromaeosauridae, and the 
Troodontidae form a monophyletic group while the 
Scansoriopterygidae, other basal birds, and probably also 
the Oviraptorosauria, form another clade. Mapping some of 
the salient features onto a temporally-calibrated 
theropod phylogeny indicates that characteristics related 
to flight and arboreality evolved at the base of the 
Paraves, earlier than the Late Jurassic. 


http://www.springerlink.com/content/387524025j71h741/


Also now available for free at:
http://digitallibrary.amnh.org/dspace/handle/2246/6087

Daniel T. Ksepka and Mark A. Norell, 2010.
The Illusory Evidence for Asian Brachiosauridae: New 
Material of Erketu ellisoni and a Phylogenetic 
Reappraisal of Basal Titanosauriformes 
American Museum Novitates 3700: 1?27