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Wrangellian

Ordovician Trilobites From Morocco

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Wrangellian

Does anyone know for sure the name, location and formation name for those large inexpensive Moroccan trilos you see for sale everywhere.. the name I have is Diacalymene ouzregui but I have also seen Flexicalymene ouzregui.. and the location is either near Erfoud, Tazoulait, and/or Alnif, Anti-Atlas Mnts. And I'm not sure what part of the Ordovician they are from - upper, middle, lower..? All too confusing. I suppose I could sort it all out if I knew the area better but I don't and it's hard to find consistent, detailed info for Moroccan fossils.

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piranha

Does anyone know for sure the name, location and formation name for those large inexpensive Moroccan trilos you see for sale everywhere.. the name I have is Diacalymene ouzregui but I have also seen Flexicalymene ouzregui.. and the location is either near Erfoud, Tazoulait, and/or Alnif, Anti-Atlas Mnts. And I'm not sure what part of the Ordovician they are from - upper, middle, lower..? All too confusing. I suppose I could sort it all out if I knew the area better but I don't and it's hard to find consistent, detailed info for Moroccan fossils.

This appears to be the current data:

Flexicalymene ouzregui

Anti-Atlas Region

Tazzarine des Aït-Atta, Tarhbalt (Maïder)

Upper Ordovician - Ashgill (lower)

Ktaoua clay and sandstone group

upper argillite formation

LINK

REFERENCE:

Destombes, Jacques (1967) Distribution et affinites des genres de trilobites de l'ordovicien de l'Anti-Atlas (Maroc).

Compte Rendu Sommaire des Seances de la Societe Géologique de France 4:133-134

Destombes, J. (1971) L'ordovicien au Maroc; essai de synthese stratigraphique.

Memoires du B.R.G.M. 73:237-263 (A. Miller/P. Novack-Gottshall/P. Novack-Gottshall)

Destombes, J., Hollard, H.; Willefert, S. (1985) Lower Palaeozoic rocks of Morocco.

In: Holland, C.H. - Lower Palaeozoic of north-western and west-central Africa. John Wiley & Sons.

Edited by piranha

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xonenine

I've been looking at these forever:

I got 5 for 5.95 +5 shipping today, listed as:

Calymene species trilobites from Morocco, North Africa and date back to 450 million years ago of the Paleozoic Era, Ordovician Period Couldn't resist, they are usually 5 to 7 dollars for 1. :)

I think I found a few decent looking ones to learn to prep a little.Maybe someone here can nail down what they are called and if they were listed right?

post-4577-0-75527800-1292198713_thumb.jpg

Edited by xonenine

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piranha

Maybe someone here can nail down what they are called and if they were listed right?

Just posted that a few moments above(before) your post Carmine - there is no revision I'm aware of.

Nice purchase you made! You're right - usually one would fetch that price. Such a deal! ;)

Edited by piranha

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xonenine

TY Piranha, one of my first real labels w all the info, hehe.Carmine.

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Wrangellian

I've been looking at these forever:

I got 5 for 5.95 +5 shipping today, listed as:

Calymene species trilobites from Morocco, North Africa and date back to 450 million years ago of the Paleozoic Era, Ordovician Period Couldn't resist, they are usually 5 to 7 dollars for 1. :)

I think I found a few decent looking ones to learn to prep a little.Maybe someone here can nail down what they are called and if they were listed right?

Piranha is right, that's what I paid for one of them, years ago! Good deal.

But I've seen conflicting dates, everything from lower to upper Ordo, and I wasnt sure if that was because the dates on the Ordovician have been revised or the formation itself has been redated.

Thanks Scott or the detailed info, but what is Ashgill, isnt that an old stage that is being phased out? and how does it correlate with the Sandbian/Katian/Hirnantian in the new system? I guess if that 450my date is still accurate it would be Katian.

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piranha

Piranha is right, that's what I paid for one of them, years ago! Good deal. But I've seen conflicting dates, everything from lower to upper Ordo, and I wasnt sure if that was because the dates on the Ordovician have been revised or the formation itself has been redated. Thanks Scott or the detailed info, but what is Ashgill, isnt that an old stage that is being phased out? and how does it correlate with the Sandbian/Katian/Hirnantian in the new system? I guess if that 450my date is still accurate it would be Katian.

I'm not sure Eric. Destombes papers are decades old. The subdivision of time periods currently in use tend to get too deep in the weeds for me.

All of the above references track back to the Ordovician so I'm at a total loss for what the correct stage(s) should be named. Shouldn't the rules of precedence apply when describing or cataloging the material going forward?

Edited by piranha

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Wrangellian

I'm not sure Eric. Destombes papers are decades old. The subdivision of time periods currently in use tend to get too deep in the weeds for me.

All of the above references track back to the Ordovician so I'm at a total loss for what the correct stage(s) should be named. Shouldn't the rules of precedence apply when describing or cataloging the material going forward?

I'm sure that's true of genus/species names but they're trying to revise the Time Scale to suit everybody around the world, I guess they're not finished with it yet, but if certain regions are going to continue their old divisions I'd like to see a correlation of the old regional ones with the new worldwide ones (Int'l Comm. on Stratigraphy) but because the dates have also been changed it makes it impossible for me to correlate them accurately. It would take someone with knowledge of the faunal changes to make that correlation.

But for now I'll just write 'Lower Ashgillian'. ;)

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hakhan

I'm sure that's true of genus/species names but they're trying to revise the Time Scale to suit everybody around the world, I guess they're not finished with it yet, but if certain regions are going to continue their old divisions I'd like to see a correlation of the old regional ones with the new worldwide ones (Int'l Comm. on Stratigraphy) but because the dates have also been changed it makes it impossible for me to correlate them accurately. It would take someone with knowledge of the faunal changes to make that correlation.

But for now I'll just write 'Lower Ashgillian'. ;)

hello everyone:

This trilobite is not far from Zagora Morocco

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Raff

this is a photo of my Flexycalimene from Morocco..

post-4634-0-89458700-1293034784_thumb.jpg

Edited by Raff

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Wrangellian

this is a photo of my Flexycalimene from Morocco..

Looks like the same ones, but most of them don't have the negative half (Nice to have both).

I wonder if the positives are just interior molds, or are they true positives (outer surface)? I can't tell from my specimen, they almost look like they're internal moulds missing their shell; maybe someone out there knows. In any case I would assume the negative impression would be of the outer surface of the animal.

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piranha

Looks like the same ones, but most of them don't have the negative half (Nice to have both).

I wonder if the positives are just interior molds, or are they true positives (outer surface)? I can't tell from my specimen, they almost look like they're internal moulds missing their shell; maybe someone out there knows. In any case I would assume the negative impression would be of the outer surface of the animal.

I would say steinkern.

EDIT: From TRILOBITA.DE and Google Translate:

In Morocco, these concretion-trilobites of locals have long been used as exchange currency. The stones are mainly Calymene-trilobites (Flexicalymene, Colpocoryphe), which can sometimes even be over 10 cm long. The concretion is it because of Trilo was there embedded in the mud - by the organic substance of the animal changed the surrounding "micro climate" in the sediment, leading to the formation of hard layers around it, that is the concretion. That is according to the reference in many fossils. Because the shell of trilobites is now gone, instead you see the "stone heart" ("Steinkern"), that is the impression of the top and bottom of the (lost) as an imprint in the rock shell, but this amazingly fine details can deliver.

Edited by piranha

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Raff

A photo from an another position

post-4634-0-65598200-1293182729_thumb.jpg

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Ordovician_Odyssey

there deffinatly calymenidae......my friend got one once.....i cant remember the exact species, but genus was deffinitly calymene..but if the proposed ID on the card was right or not, im not sure.....

Edited by trilobite guy

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piranha

I posted this on another thread although it's very useful to the present discussion. The information underscores the complexity of classification:

Additional research indicates that among the Moroccan calymenids the genus Colpocoryphe on casual observation also appears to be the same trilobite as F.ouzregui and F.tazarinensis. The main differentiation between Colpocoryphe and Flexicalymene being a straight projection in front of the glabella in the former and a curved upturned projection in the latter. All of the genera are mostly problematic given the generally beat up and weathered condition of the fossils. Recent expert opinion is reticent to inform with any degree of specificity given the lack of complete specimens for evaluation.

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Wrangellian

So my suspicion that I was looking at an internal mold was correct, as the shell itself is gone. Dang, now I have to look for a specimen with the negative part to get a look at the external detail! No wonder they're never more than $5 or so apiece..

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