Re: Everything you know about the Iren Dabasu age is wrong...

[tholtz@geol.umd.edu]

>   Iren Dabasu has at least one dinosaur in common with
> the Baynshirenian beds of Outer
> Mongolia-Alectrosaurus. There is no doubt that the
> Baynshirenian beds far underlie the Nemegt.

Except, of course, that the Bayn Shire small tyrannosaur material hasn't
been demonstrated to actually come from Alectrosaurus olseni, which is at
present a poorly diagnosed taxon.

>>   The distance can be three miles and still indicate
>> a drastic change in
>> climate:
>
>  Nemegtian taxa were very wide ranging. Tarbosaurus
> occurs in southern China, well south of Iren Dabasu
> where Alectrosaurus is known. The absence of
> Tarbosaurus there, like the absence of Mesolanistes,
> and Mongolemys etc argues against a Nemegtian age.

Actually, given that the Iren Dabasu has had far from a great number of
field seasons, I would be cautious about saying what's really there.

Much like I would be cautious about dismissing the stratigraphic
conclusions of a paper prior to reading it. (Yes, I admit: I'm pretty
skeptical. But let's see what they have to say!)

                Thomas R. Holtz, Jr.
        Senior Lecturer, Vertebrate Paleontology
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
        Mailing Address:
                Building 237, Room 1117
                College Park, MD  20742

http://www.geol.umd.edu/~tholtz/
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