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aek

Northern Illinois Ordovician Quarry

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aek

This is my first trip report on the forum, an attempt to organize my finds and hopefully get some help with identification. The quarry was located near Rockford, Illinois, Ordovician period. 

 

Recepticulites, in the field.

 

IMAG7903.jpg

 

Not sure what this impression is. Any ideas?

 

IMAG8131_1.jpg

 

An assortment of brachiopods and gastropods in beautiful bone-white chert.

IMAG8128_1.jpg

IMAG8129_1.jpg

 

Not sure what this is...sorry for the blurriness, my phone doesn't have the best camera.

 

IMAG8136_1.jpg

 

Gastropod and recepticulites chunk

 

IMAG8130_1.jpg

 

Top and bottom halves of recepticulites.

 

IMAG8133_1.jpg

 

Not sure what these tentacles are... Bryozoans perhaps?

 

IMAG7914_1.jpg

 

Here they are under the microscope. They appear golden only because I naively used a brass brush to clean them (oops!)... a nice effect nonetheless..

 

IMAG7925.jpg

 

 

IMAG7927.jpg

 

Thanks for looking!

 

 

 

 

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Fossildude19

Welcome to the Forum. :) 

 

That's one of the nicest Receptaculites sp. I have seen on here!  :blink: :wub:

 

I think your 1st unknown is a worn imprint of a Receptaculites. 
Your second unknown looks like a broken gastropod to me. 

The "tentacles" are most likely bryozoans. 

Thanks for posting these. 

Regards, 

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Fossildude19

Don, 

Thanks for that info - trilobite does make more sense to me. 

Boy I'm glad we have you and other knowledgeable people here on the Forum!

Best regards, 

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Raggedy Man

What quarry did you hunt? Several quarries in that area have different formations exposed. Wouldn't be the the Vulcan quarry would it?

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digit

I agree that your Recepticulites/Fisherites is the nicest specimen I've ever seen. I have one of these from my childhood in Chicago when all I could find were the occasional mollusk steinkern, barnacle, or other (at the time unidentifiable) fossil. I need to go find that box of childhood fossils and see what I have from decades ago. I'd love to get out and do some fossil hunting in Rockford (where I likely found my childhood fossils) next time I'm back up in Chicago. I'm up here now but it is too cold and damp to think about picking around outside for fossils.

 

Cheers.

 

-Ken

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fossilized6s

I agree with Fisherites. I just found my first examples of these strange fossils in September in Minnesota. I believe scientists are leaning towards plants, like giant underwater sunflowers. 

 

Very nice example. 

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digit

Coralline algae is the current hypothesis I believe. For some time they were thought to be corals I think and were called 'sunflower corals' due to the resemblance to the seeds in a sunflower. I think they are pretty cool--hadn't a clue what it was when I was a pre-teen (in the ancient days before TFF). Would enjoy looking for new specimens again in the present--duly added to my fossil bucket list. :)

 

Cheers.

 

-Ken

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piranha

Actually, receptaculitids are still unresolved.

 

text from:

 

Nitecki, M.H., Mutvei, H., & Nitecki, D.V. (1999)

Receptaculitids: a phylogenetic debate on a problematic fossil taxon.

Springer Scientific Publishing, 241 pp.

 

We know that we have succeeded only in showing that receptaculitids were neither sponges, archaeocyathids, nor dasyclads, because the cumulative receptaculitid characters are not those of sponges or of algae. It is surely premature to ask what they were-we must still wait to know that. We are far from providing final answers, but we hope that others will be stimulated to ask new questions, and to accept receptaculitids as more than the sum of their characters. The preponderant lesson from our morphological analyses has shown us that complete understanding of the nature of the receptaculitids is not yet possible; therefore, in order to build a strong case on the nature of receptaculitids we either had to endlessly speculate, or admit our ignorance. The German idioms and expressions have changed since Rauff wrote (1892a:648), and the current rendition of his conclusions as shown in our Dedication (p. v) may now be rephrased:


"Receptaculitids are again removed from their taxonomic position, without resolving their systematics, and it is hoped that the present paper will form the bases for future phylogenetic analyses."


We now believe that we do not know enough to be definitive, and have been left no choice but to follow Rauff in retaining receptaculitids in the Problematica.

 

 

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aek
8 hours ago, Fossildude19 said:

Welcome to the Forum. :) 

 

That's one of the nicest Receptaculites sp. I have seen on here!  :blink: :wub:

 

I think your 1st unknown is a worn imprint of a Receptaculites. 
Your second unknown looks like a broken gastropod to me. 

The "tentacles" are most likely bryozoans. 

Thanks for posting these. 

Regards, 

Thanks for the insight!

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aek
8 hours ago, FossilDAWG said:

Nice fossils!

 

The large recepticulitids you show (including photo 2) are now named Fisherites.  The genus Recepticulites was revised several years ago; some species were retained in that genus, but many were found to be different enough to merit their own genus, and this new genus was called Fisherites.

 

The blurry unknown in photo 5 is a nautiloid cephalopod.  The gentle curve suggests an oncocerid such as Oncoceras or Beloitoceras.

 

This is more uncertain, but I suspect the last few photos may show disarticulated trilobite bits.  The last photo looks like a side of a free cheek, with a bit of an eye showing.  The fossil in the second-to-last photo might be a fragment of the frill of a harpid trilobite such as Dolichoharpes.  Tim's suggestion that it is a bryozoan is reasonable, but the "holes" (assuming they are holes and not bumps) seem to me to be too irregular and the wrong shape to be bryozoan zooids.

 

Don

Thanks for the clarification on the Fisherites- good to be up to date! Interesting about the disarticulated trilobite parts. I think I found more trilo bits in other pieces too.

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aek
7 hours ago, digit said:

I agree that your Recepticulites/Fisherites is the nicest specimen I've ever seen. I have one of these from my childhood in Chicago when all I could find were the occasional mollusk steinkern, barnacle, or other (at the time unidentifiable) fossil. I need to go find that box of childhood fossils and see what I have from decades ago. I'd love to get out and do some fossil hunting in Rockford (where I likely found my childhood fossils) next time I'm back up in Chicago. I'm up here now but it is too cold and damp to think about picking around outside for fossils.

 

Cheers.

 

-Ken

Thanks, that's why I'm indoors cataloging- too cold and rainy!

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aek
5 hours ago, fossilized6s said:

I agree with Fisherites. I just found my first examples of these strange fossils in September in Minnesota. I believe scientists are leaning towards plants, like giant underwater sunflowers. 

 

Very nice example. 

Thanks!

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aek
7 hours ago, Raggedy Man said:

What quarry did you hunt? Several quarries in that area have different formations exposed. Wouldn't be the the Vulcan quarry would it?

It was in Roscoe

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aek

I was about to discard this piece of chert tonight but noticed something peculiar. Looked under the microscope and found a tiny Hormotoma measures 3mm

hormotoma.jpg

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JimB88

Nice finds. Your in my old stomping grounds! See if you can get into the Stateline quarry in South Beloit..lotsa good Galena mbr. goodness!

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digit

I used to do my dive training in Pearl Lake in South Beloit (just below the Wisconsin-Illinois state line). An old rock quarry that they stopped pumping out and allowed to fill. On a good day it was 5 foot visibility and 55F temperature requiring lots of layers of neoprene). That area of the state is not that far from the Chicagoland area and I need to research some interesting fossil hunting localities for when I'm back in Chicago during the warmer months.

 

Cheers.

 

-Ken

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Raggedy Man
On 11/23/2016 at 9:15 PM, aek said:

It was in Roscoe

Im fairly certin I know what quarry. You werw probably in the Galena Group, Dunleith and Wise Lake Formations which explains the chert brachiopods and gastropods. It also explains the wonderful preservation of your Fisherite. The lower Wise Lake Formation contains calcite replaced gastropods and brachiopods though rare. The trilobite fragment of the Dolichoharpes looks like it's pyritized a bit. Definitely an interesting find. 

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aek
On 11/24/2016 at 0:36 PM, JimB88 said:

Nice finds. Your in my old stomping grounds! See if you can get into the Stateline quarry in South Beloit..lotsa good Galena mbr. goodness!

Thanks! I'll see if I can check it out in the spring.

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