new papers(Chinese Ccience Bulletin)

["Kazuo TAKAHASHI" <pantheon@kw.netlaputa.ne.jp>]

Further support for a Cretaceous age for the feathered-dinosaur beds of
Liaoning, China: New 40Ar/39Ar dating of the Yixian and Tuchengzi Formations

Chinese Ccience Bulletin Vol.47 No.2 Jan.2002
http://www.scichina.com/ky/0202/ky0135.stm


C. C. Swisher III1, WANG Xiaolin2, ZHOU Zhonghe2, WANG Yuanqing2, JIN Fan2,
ZHANG Jiangyong2, XU Xing2, ZHANG Fucheng2 & WANG Yuan2


Abstract  We report new 40Ar/39Ar dating results obtained from total fusion
and incremental-heating analyses of sanidine and
 biotite from three tuffs found interbedded within the fossil-bearing
deposits of Liaoning, northeast China. The first is a new
 sample of the Bed 6 Sihetun tuff from the Yixian Formation, previously
dated by our team as middle Early Cretaceous, and
recently considered by Lo et al., partially reset due to metamorphism from a
nearby basaltic sill. The second is the Yixian Bed 9
 tuff from Hengdaozi considered by Lo et al. to be unaffected by
metamorphism and whose age, based on total fusion 40Ar/39Ar
 dating of biotite, argues for a Jurassic age for the Yixian Formation. The
third tuff is a previously undated tuff from the upper
 part of the underlying Tuchengzi Formation. Single crystal total fusion
40Ar/39Ar analyses of the Sihetun sanidine showed
 homogeneous radiogenic Ar, Ca/K ratios, excellent reproducibility and gave
a mean age of 125.0 !A 0.18 (1SD) !A 0.04 (SE) Ma.
Single sanidine crystal total fusion 40Ar/39Ar analyses of the Hengdaozi
tuff gave a mean age of 125.0 !A 0.19 (1SD) !A 0.04
 (SE) Ma, which is indistinguishable from the Sihetun tuff. The Tuchengzi
Formation tuff gave a mean age of 139.4 !A 0.19 (1SD)
 !A 0.05 (SE) Ma. Detailed laser incremental-heating analyses of biotite
from Sihetun, Hengdaozi, and Tuchengzi tuffs show
 disturbed Ar release patterns and evidence of trapped argon components. We
conclude from these analyses that the total fusion
 dates on biotite by Lo et al. are erroneously old and isotopic dating of
both biotite and sanidine from tuffs of the Yixian Formation
 point to a middle Early Cretaceous age.  The upper part of the Tuchengzi
Formation can be referred to the Early Cretaceous.



A nearly completely articulated rhamphorhynchoid pterosaur with
exceptionally well-preserved wing membranes and 。ーhairs。ア
from Inner Mongolia, northeast China

Chinese Science Bulletin Vol.47 No.3 Feb.2002
http://www.scichina.com/ky/0203/ky0226.stm
photo
http://www.scichina.com/ky/0203/2kyfm03.stm

WANG Xiaolin, ZHOU Zhonghe, ZHANG Fucheng & XU Xing



Abstract  We report a new and nearly completely articulated rhamphorhynchoid
pterosaur, Jeholopterus ningchengensis gen. et sp. nov.,
with excellently preserved fibres in the wing membrane and 
!°hairs!± in
the neck, body and tail regions. Many of its characteristics
such as a short neck, short metacarpals and distinctively long fifth pedal
digit are characteristic of rhamphorhynchoids. The new
species can be further referred to the !Rstrange!￣ short-tailed
rhamphorhynchoid family Anurognathidae. It is much more complete
than the other known members of the family, namely, Anurognathus from
Solnhofen, Germany, Batrachognathus from Karatau, Kazakhstan,
and Dendrorhynchoides from Beipiao, Liaoning Province, China. The new
pterosaur also shows that the wing membrane is attached to the
ankle of the hind limb. The pedal digits are webbed. Furthermore, the
!°hair!± of Jeholopterus bears some resemblance to the hair-like
integumental structures of the feathered dinosaur Sinosauropteryx although
there is yet no direct evidence to argue for or against their
homology.

高橋　和男　TAKAHASHI ,KAZUO
http://www.NetLaputa.ne.jp/~pantheon/
pantheon@kw.netlaputa.ne.jp