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Re: Archies in the Morrison?!
> You read my mind! I would _LOVE_ to find some nice lithographic
> limestones of Late Triassic/Early Jurassic age somewhere! And,if they
> _don't_ exist anywhere, barring complete erosion, could anyone suggest a
> reason why they _don't_ occur in those time periods? (Barring lack of
> exposure, too...)
If I understand my historic geology right...during the Late
Triassic/Early Jurassic most of the continents lacked epi-continental
seaways and off shore shelves were quite narrow and deep. Also this time
was marked by a lot of rifting...great for evaporates but lousy for those
calm, shallow lagoonal deposits.
I suggest a better source for small vertebrates are the playa deposits
and fine grain mud deposits (mudflats---great for footprints).
---John Schneiderman (firstname.lastname@example.org)