Re: Zhonghuaornis, Perpiaoornis, Weiyuornis and other things on Hou's site

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

Jaime A. Headden wrote-

> The arguments for a
> Jurassic level remain solely on phylogeographical import, including the
> earlier papers, most of the taxonomic papers, and especially detailed in
> Luo's Refugium hypothesis.

I don't know about other fossils, but the dinosaurian record of Yixian fauna
hardly supports a Jurassic age-

Basal beds of Lower Yixian Formation (not radiometrically dated)
Sinovenator- a troodontid, all but Koparion known from the Cretaceous.
Liaoceratops- a neoceratopsian, only known from the Cretaceous.

Jianshangou beds of the Lower Yixian Formation (radiometrically dated as
Middle Barremian)
Sinosauropteryx, whose resemblence to Compsognathus was overexaggerated and
probably doesn't belong to the Compsognathidae.  There are many basal
coelurosaurs from the Early Cretaceous in any case (Scipionyx, Nqwebasaurus,
Nedcolbertia) including compsognathids (Aristosuchus, Santana form).
Protarchaeopteryx, a maniraptoran, perhaps enigmosaurian, both almost
exclusively known from the Cretaceous.
Beipiaosaurus, a segnosaurian, known from the Cretaceous, not the Jurassic.
Caudipteryx- an oviraptorosaur, also common in the Cretaceous and unknown in
the Jurassic, most closely resembling Nomingia, from the Campanian.
Sinornithosaurus- a eumaniraptoran, much more common in the Cretaceous and
closely resembling Bambiraptor, from the Campanian.
Microraptor- another eumaniraptoran.
Confuciusornis- a pygostylian, only known from Cretaceous deposits
elsewhere.
Changchengornis- another pygostylian.
Eoenantiornis- another pygostylian.
Liaoningornis- an enantiornithine, most similar to Early Cretaceous
Eoalulavis.
Psittacosaurus- known from Early Cretaceous strata in many other Asian
localities.

I don't see any evidence for a Jurassic age when taxa are compared to those
in other localities.  Far from it, this supports an Early Cretaceous if
anything.  The whole idea the dinosaurs were like Jurassic taxa was based on
the inaccurate comparisons of Sinosauropteryx and Confuciusornis to
Compsognathus and Archaeopteryx respectively.  Similarily, there doesn't
seem to be any reason for a local refugium of Jurassic taxa in the Yixian.

MIckey Mortimer