Aurornis, new Jurassic avialan dinosaur from China

[Ben Creisler <bcreisler@gmail.com>]

From:  Ben Creisler
bcreisler@gmail.com


New in Nature, Aurornis xui:



Pascal Godefroit, Andrea Cau, Hu Dong-Yu, François Escuillié, Wu
Wenhao & Gareth Dyke (2013)
A Jurassic avialan dinosaur from China resolves the early phylogenetic
history of birds.
Nature (advance online publication)
doi:10.1038/nature12168
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12168.html


The recent discovery of small paravian theropod dinosaurs with
well-preserved feathers in the Middle–Late Jurassic Tiaojishan
Formation of Liaoning Province (northeastern China) has challenged the
pivotal position of Archaeopteryx, regarded from its discovery to be
the most basal bird. Removing Archaeopteryx from the base of Avialae
to nest within Deinonychosauria implies that typical bird flight,
powered by the forelimbs only, either evolved at least twice, or was
subsequently lost or modified in some deinonychosaurians. Here we
describe the complete skeleton of a new paravian from the Tiaojishan
Formation of Liaoning Province, China. Including this new taxon in a
comprehensive phylogenetic analysis for basal Paraves does the
following: (1) it recovers it as the basal-most avialan; (2) it
confirms the avialan status of Archaeopteryx; (3) it places
Troodontidae as the sister-group to Avialae; (4) it supports a single
origin of powered flight within Paraves; and (5) it implies that the
early diversification of Paraves and Avialae took place in the
Middle–Late Jurassic period.



Also a news story:

http://www.nature.com/news/new-contender-for-first-bird-1.13088