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Re: Tsagayan/Udurchukan age-Campanian?



--- "Jaime A. Headden" <qilongia@yahoo.com> wrote:

> Tim Donovan (uwrk2@yahoo.com) wrote:
> 
> <Bolotsky and Godefroit (June 2004 JVP, page 351)
> cited research by
> Markevich and Bugdaeva (and Godefroit) which
> indicated that all three
> Tsagayan or Udurchukan localities-Blagoveschensk,
> Kundur and Jiayin-and
> the Miho Group of Sakhalin Island, which yielded
> Nipponosaurus- are
> synchronous and belong to the Aquilapollenites
> subtilis/Wodehousesia
> spinata palynozone, spposedly indicative of a late
> Maastrichtian age.
> 
> But ammonite evidence indicates that the unit which
> yielded Nipponosaurus
> is of early Campanian age, if not older!(March 2004
> JVP, page 146)
> Apparently the Aquilapollenites
> subtilis/Wodehousesia spinata palynozone,
> the basis for a putative late Mastrichtian age, can
> be as old as basal
> Campanian, perhaps even late Santonian, in Asia. In
> view of the primitive
> state of Amurosaurus, an early Campanian age seems
> perfectly plausible,
> far more so than the age currently given.>
> 
> From Suzuki, Weishampel and Minoura (2004, _JVP_
> 24(1): pg. 146):
>   "Since South Sakhalin no longer belongs to Japan,
> it is presently
>    impossible for additional geological research to
> be conducted at the
>    Kawakami colliery by Japanese researchers. Thus,
> the details of this
>    specific locality are no longer clear. Moreover,
> field notes made at
> the
>    time of the excavation are missing. Nagao (1936),
> however, did note
> that
>    the locality of the type specimen of
> *Nipponosaurus* also produced
>    fossils of *Puzosia japonica* (now *Parapuzosia
> japonica*) and
>    *Inoceramus schmidti* (now *Sphenoceramus
> schmidti*), both of which
>    belong to the middle of the Upper Ammonites beds
> (now Upper Yezo Group;
>    Matumoto, 1951b). Recent biostratigraphic studies
> indicate that the
>    range of *P. japonica* and *S. schmidti* are
> limited to the lower
>    Campanian (Takayanagi and Matsumoto, 1981;
> Tashiro et al., 1995).
>    Although *S. schmidti* is known only from the
> lower Campanian, dubious
>    referrals of *S. schmidti* to *S. sachalinensis*
> are often made
>    (Hayakawa, pers. comm.); the latter is also known
> from the upper
>    Santonian. Consequently, the age of
> *Nipponosaurus* probably ranges
> from
>    the late Santonian to the early Campanian."
> 
>   Refs given:
>   Matumoto T. 1942. Fundamentals in the Cretaceous
> stratigraphy of Japan.
>     _Memoirs of the Faculty of Science, Kyushu
> Imperial University, Series
>     D, Geology_ 1:129-280.
>   Matumoto T., and I. Obata. 1979. _in_ Obata, I.
> 1979 [The ages of the
>     fossil reptiles in Japan.] _Kaseki_ 29:5358. [in
> Japanese]
>   Nagao T. 1938. On the limb-bones of *Nipponosaurus
> sachalinensis* Nagao,
>     a Japanese hadrosaurian dinosaur. _Annotationes
> Zoologicae Japonenses_
>     17:311-317.
>   Takayanagi Y., and T. Matsumoto. 1981. Recent
> advances in the Cretaceous
>     biostratigraphy of Japan by coordinating mega-
> and micro-fossils.
>     _Recent Progress of Natural Sciences in Japan_
> 6:125-138.
>   Tashiro M., H. Maeda, S. Wako, K. Hayakawa, M.
> Kano, and N. Arakawa.
>     1995. On "*Sphenoceramus schmidti* (Michael,
> 1899)" from Upper
>     Cretaceous System from south-west Japan.
> _Research Report of Kochi
>     University (Natural Science)_ 44 27-46. [in
> Japanese]
> 
>   Ah, my problem with this issue is that there
> doesn't appear to be any
> clear stratigraphic or locality information. This is
> a problem, 


  OK but this is still a serious potential problem for
the current age of the Tsagayan, which should no
longer be assumed on the basis of W. spinata unless
confirmed by  further investigation at the
Nipponosaurus site.


>since at
> some places, a single locality can span formations,
> stages, and even eras
> of time, especially at sections comprising
> Cretaceous--Paleogene periods
> in northern Europe, the Jurassic section in central
> Europe, the Early
> Cretaceous at Isle of Wight, and all those lovely
> sections that expose the
> K/T (now, I guess we may need comfiness with B-Pg,
> but K/T owes as much to
> faunal veriation as to geology, so using Tertiary is
> just as easy if only
> using "T" for the well-known label). Other, more
> relevant sections, are
> the Hermiintsab locality, which exposes the Baruun
> Goyot Formation AND the
> Nemegt Formation,


 The contact is conformable so the temporal difference
isn't so great in this case.

> as well as the Nemegetu locality,
> and that the locality
> of Ukhaa Tolgod shows many stratigraphically arrayed
> sublocalities, not
> all of which are isolated to the exact same period
> of time. So should we
> expect a fossil that comes from a locality and all
> other specimens from
> that locality to be the exact same age?
> 
>   Why cannot pollen and foram fossils constrain a
> date while inverts like
> ammonites expand it? Pollen and forams will be
> subject to more immediately
> observable evidence of evolution in their "simple"
> anatomies, leading to
> marked change at distinct times, carried in extant
> studies as well as
> extinct forms, allowing them to be used for time
> constraint. So why should
> we believe that such data as the above mean that the
> ammonite information
> is MORE likely to be true than the foram/pollen
> data? And what does
> *Amurosaurus* have to do with *Nipponsaurus,*


 I didn't say it was closely related to Nipponosaurus,
just that its primitive state seems more consistent
with an older age than late Maastrichtian.



> especially if the Suzuki et
> al. offer it is related to *Hypacrosaurus*?


   IIRC a species of Hypacrosaurus is known from the
upper Two Medicine formation, so it wouldn't be
surprising if a close relative was present in the
early Campanian.

> 
> <The Tsagayan/Udurchukan localities are not
> necessarily as old as early
> Campanian, but I think they may all be Campanian,
> judging by their
> parasaurolophines etc and definitely predate the
> Nemegtian. It was
> probably only by the latter period-c mid
> Maastrichtian-that Wodehouseia
> spinata, long established in east Asia, spread to
> America-via the same
> Bering bridge which enabled Saurolophus to spread to
> Asia- and became
> representative of the late Maastrichtian of NA.>
> 
>   *Parasaurolophus* (*P. tubicen*) is known from the
> lower Maastrichtian
> Kirtland Formation of New Mexico.


  I recall the De-na-zin has been radiometrically
dated at late Campanian. And Parasaurolophus is not
known from the Naashoibito.



> This is contiguous
> with everyone else's
> current research on the Nemegt Formation's
> allocation to the uppermost
> Campanian or lower Maastrichtian 

  Including Shuvalov? See The Age of Dinosaurs in
Russia and Mongolia. He considers the Nemegt
Maastrichtian, as do others.



>(as it is
> equivalent in some respects to
> both the upper Campanian Dinosaur Park Formation and
> the overlying lower
> Maastrichtian Horsehoe Canyon Formation). Thus,
> Urduchukan may also
> indicate some of its fossils derive from a lower
> Maastrichtian level,
> perhaps even the holotype of the "parasaurolophine"
> *Charonosaurus*
> itself.

 AFAIK, no parasaurolophines are known from the
Maastrichtian of America and no Saurolophus from the
Campanian. The Nemegt appears to be younger than the
units yielding parasaurolophines-the De-na-zin,
Laiyang and Jiayin.



 If the palynology shows a long-lived
> *Wodehousia,* long held to be
> a Maastrichtian fossil, or constrain beds containing
> it to the upper
> Maastricthtian, it would show that many verts
> evolved to different areas
> when they migrated across land bridges and became
> extinct in their endemic
> regions (gosh, like that never happens).
> 
>   Cheers,
> 
> =====
> Jaime A. Headden
> 
>   Little steps are often the hardest to take.  We
> are too used to making leaps in the face of
> adversity, that a simple skip is so hard to do.  We
> should all learn to walk soft, walk small, see the
> world around us rather than zoom by it.
> 
> "Innocent, unbiased observation is a myth." --- P.B.
> Medawar (1969)
> 
> 
> 
=== message truncated ===



                
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