new Ordovician lagerstaette in Iowa

[Joe Botting]

Hi folks,
You might be interested to know that there's a new discovery from over the Atlantic. Deposits with a useful amount of soft-tissue preservation are extremely rare in the Ordovician, which is why we feel so smug about Builth. So far, the only diverse soft-bodied faunas published are from the Soom Shale in South Africa, and Beecher's Trilobite Bed in New York... and now there's another from around Llandeilian age in Iowa.

Liu Huaibao, McKay,R. M., Young, J. M., Witzke, B. J., McVey, K. J. and Liu Xiuying, 2006: A new lagerstatte from the Midle Ordovician St. Peter Formation in northeast Iowa, USA. Geology 34, 969-972.

It's a weird fauna - mostly conodonts, vermiform things, phyllocarid crustaceans, linguloids (the only shelly fossils!), fish and eurypterids. It sounds like there will be quite a high diversity when it's all been looked at properly. The preservation is in a newly-discovered shale unit in an otherwise sandy (coastal to aeolian) deposit, and the odd fauna suggests restricted conditions. So it's not what we really want, i.e. a fully marine, 'normal' community, but it's well worth having!

If you're interested, the (short) abstract is at:

geology.geoscienceworld.org/cgi/content/abstract/34/11/969

Joe

[mosasurfiend]

I didn't know that about Iowa and read that with interest. I did find some more info with some pics and graphs that may be of interest to others here.

www.igsb.uiowa.edu/Browse/Lagerstatte/Lagerstatte.htm

[pleecan (Peter Lee)]

Thanks for the link Mosasurfiend.. you are on a roll.... I also see that Fiddlers Green Formation where I found tiney Eurypterids is also consider a Lagerstatten... interesting stuff. Peter

[solius]

There are also some new ones that suggest soft tissue preservation is more common in the fore-arc basin of Upstate New York than was previously thought. I was fortunate enough to collect from this one of these a couple of years ago, about 70 or 80 Km north of Walcott's find, in New York.

It was recently published: geology.geoscienceworld.org/cgi/content/abstract/37/10/907

[solius]

[iEDIT[/i]: Oops, that should read "back-arc"

My mantra: Inebriation fogs the brain!

[pleecan (Peter Lee)]

Thanks for the link to the article Solius.... soft tissue preservation is always an interesting subject! I do miss your posts at the Fossil Forum. Not too many are that interested in invertebrate at that site. Glad that you are posting on this site. PL

[solius]

Thanks for the kind words, sir. I had contemplating leaving "there" for a while... for various reasons. In fact, I have left several times, but always returned... maybe, one of these days, I will return???

But YEAH! Soft tissue preservation... now, that defines "cool". Recently, I saw a rusophycus that preserved the "legs", and "antennas"(no less!!!) of an asaphid.

A first in ichno??? At least in the Ord??? Soon, will tell.

[Joe Botting]

Rusophycus with leg and antennal impressions is seriously impressive... what sort of rock is it in?

I've seen trace fossils from starfish showing tube feet imprints, but not ones I've found myself. There's still quite a lot of mystery over exactly how these high-fidelity traces get preserved, but I've seen a few that blur the line between traces and external moulds of soft tissue. There's a whopping great worm trace/mould in an ash bed we must describe this year...

Thanks for the link to the paper too - I know Una vaguely, so must get a reprint off her!

[nandomas]

hello everyone, I am new here. Thanks to share this new interesting location.

Nando

[Joe Botting]

Hi Nando - welcome aboard! Please do feel free to post whatever you find interesting... with any luck it's going to get busier on here soon!

[pleecan (Peter Lee)]

Thanks Nando for joining... I am hoping more from The Fosssil Form will stop by and visit this site!
PL