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On Sat, 11 Oct 1997, Stanley Friesen wrote:
> Sounds nice at first glance. But he misses one major fact. The Lance and
> Hell Creek Formations were laid down on a broad coastal plain, and
> _Triceratops_ is stupendously abundant in these beds. _Triceratops_ is
> found even in the lowest parts of the Hell Creek, where it immediately
> overlays the coastal dunes of the Fox Hills Formation. (In fact parts of
> the Hell Creek immediately above the Fox Hills derive from a lagoonal
> environment). This puts _Triceratops_ right by the shore - separated form
> it by nothing but a lagoon, a few sand dunes and a beach.
> And most of the earlier ceratopsians from the American midwest come from
> similar situations. In short, except for some protoceratopsids,
> ceratopsians are virtually unknown from inland formations.
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.