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Re: CERATOPSIAN
At 10:22 PM 10/12/97 -0400, Scott McCray wrote:
>
>
>
> Does this indicate that ceratopsians lived on coastal plains, or
>that they were deposited on coastal plains by rivers?
> My own experience with the Hell Creek Formation is that
>_Triceratops_ was being deposited in a fluvial system. This being
>so, it's a little difficult to say with confidence how far material
>may have gone downstream before deposition.
>
Well, there is some indirect evidence. The more inland sediment series
tend to lack Triceratops, and to contain Montanaceratops and/or
Leptoceratps. If the Triceratops came from upland areas, they should be
*more* common inland, not less.
Secondly, as one of the two most common species in the Lance and Hell Creek
(and equivalents), it seems to me unlikely that the specimens were washed
in from any great distance.
I am not entirely sure, but I *think* some of the specimens come from
fine-grained overbank deposits, which is usually a fair indication of a
proximal source.
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