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Re: Achelousaurus bed date

>        Dumb question, but I want to be sure:  The recent _Einiosaurus_
>posting specifically lists the age as Late Campanian; the _Achelousaurus_
>post has no such age listed.  Both are from the Two Medicine Formation.
>Are they (from) the same age?

_Einiosaurus_ is from near the top of the Upper Two Medicine Formation,
_Achelousaurus_ is from even higher up in the Upper Two Medicine Formation.
They might both be late Campanian (lower case "late", because there are no
formal subdivisions of this age), or _Achelousaurus_ *might* be from the
earliest Maastrichtian.  If I remember correctly, Sampson and colleagues are
working on getting radiometric dates for the Two Medicine units.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661