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Middle Jurassic Avialae?



Richard Travsky wrote-

>  http://www.uchospitals.edu/news/2003/20030326-salamanders.html

Which corresponds to a paper in Nature-
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v422/n6930/a
bs/nature01491_fs.html
In this paper, the salamanders are said to be from-
Daohugou, Ningcheng County, Inner Mongolia, China; Middle Jurassic
Jiulongshan Formation (Bathonian).
They specify "The new salamander fossils were recovered from volcanic
deposits of pale-grey shales and tuffs at Daohugou Village, Inner Mongolia,
China.  The assessment of the Middle Jurassic (Bathonian) age of the fossil
beds is based on biostratigraphic analysis of insect and vertebrate
assemblages (9-13)."

References 9-13 are-
9. Wang, S. et al. Stratigraphical Lexicon of China: The Jurassic System
(Geological Publishing House, Beijing, 2000)
10. Krzemiski, W. & Ren, D. Praemacrochile chinensis n. sp. from the Middle
Jurassic of China (Diptera: Tanyderidae). Pol. Pis. Entomol. 71, 127-129
(2002)
11. Ren, D. & Oswald, J. D. A new genus of kalligrammatid lacewings from the
Middle Jurassic of China (Neuroptera: Kalligrammatidae). Stuttgart. Beit.
Nat. B 33, 1-8 (2002)
12. Ji, Q. & Yuan, C. Discovery of two kinds of protofeathered pterosaurs in
the Mesozoic Daohugou Biota in the Ningcheng region and its stratigraphic
and biologic significances. Geol. Rev. 48, 221-224 (2002)
13. Ren, D. et al. On the biostratigraphy of the Jurassic fossil beds at
Daohugou near Ningcheng, Inner Mongolia. Geol. Bull. China 21, 584-591
(2002)

Sound familiar?  You might recall Zhang et al. (2002) in their description
of Epidendrosaurus, where the locality was given as-
"The material described in this paper was collected from a new locality,
Daohugou, in east Nei Mongol, northeast China, which is west of Liaoning
Province. Many salamanders (Wang 2000), plants and insects (Zhang 2002) have
recently been discovered from this new locality. It is notable that an
anurognathid rhamphorhynchoid pterosaur with beautiful hair covering the
whole body has also been reported from this locality (Wang et al. 2002)."

It seems both come from the same locality, which has been dated as Bathonian
based on insect biostratigraphy (which I'll trust over vertebrate
biostratigraphy anyday).  Perhaps an absolute age will be available from the
tuffs.  Note the Langi Formation overlies it and is dated as Callovian based
on potassium-argon, while above that is the Berriasian Tuchengzi Formation
(Swisher et al., 2002).  Apparently there is a Wafangdian Formation between
the Langi and Tuchengzi, which would be Late Jurassic (which the Tuchengzi
may also extend into).  So there is a nice set of formations between the
Dauhugou and Yixian, as might be expected for such an age difference.  This
would tend to indicate Epidendrosaurus is distinct from Scansoriopteryx
(which is from the Late Barremian, being from the same locality as
Liaoxiornis), and that the Scansoriopterygidae (Czerkas and Yuan, 2002) was
fairly long lived.  It also makes Epidendrosaurus the earliest known
avialan, based on the phylogenetic hypotheses of Zhang et al. (2002),
Czerkas and Yuan (2002) and myself (DML 2002).  At long last Avialae and
Deinonychosauria appear in the fossil record at the same time.

Mickey Mortimer