[meteorite-list] Scientists Excited About Potential Impact CraterSite in...

[MexicoDoug at aol.com]

Sterling & Ron commented::

> If a  meteorite created the structure, it hit some 300 million years ago
> when  mid-Missouri was part of an ancient Jurassic Age sea. The strike
>  obliterated plant-like crinoids, Koeberl said.

Ancient Jurassic Sea 300 million years ago?  ???????  I don't  think so...So, 
what does the crinoidal limestone (Burlington Limestone) look  like 
there...did it "obliterate" FOSSILIZED REMAINS or the CRINOID ANIMALS  THEMSELVES...any 
more info on this comment?  Is it an assumption or based  on some observation 
of some crinoids...I thought their age was ~345 million  years old in that 
locality...but the article mentions a strike 300 million years  old...and the 
article refers to a Jurassic age...Jurassic is only 136-190  million years old 
(in the Mesozoic), so the article seems to have left an  ambiguous 
chronostratigraphy- and that limestone is from the Paleozoic  Mississipian, or 
pennsylvanian, I think...I hope someone could elucidate a bit  on this...Also, crinoids 
are animals stuck with"plant-like" and the misnomer  "Sea Lilies", but look a 
lot more like brittlestars, the feathery starfish in  many parts of the world, 
just they frequently had long stems in prior ages that  now look like stacks 
of coins when found fossilized.
Saludos, Doug