Four is a crowd (in a good way)

[FossilDAWG]

I was splitting up some Conasauga Formation shale from the Chatsworth area exposure @Nimravis and @MeargleSchmearglhave been posting about recently.  This was material I brought back 2 or 3 years ago and have had sitting around.  I found numerous specimens of the usual Aphelaspis the site is noted for.  Then I split a small piece and here's what popped out:

Four complete Agnostus inexpectans agnostid trilobites!!  Talk about "inexpected", it's hard to find one of these complete much less four on the same piece of shale.  

Some other views:

 

Don

[Tidgy's Dad]

WOW ! 

I've got a few Aphelaspis myself, thanks to Ralph, and a I know how rare these are. 

Lots of bits too! 

Lucky chap. 

[oldtimer]

It's got four on one plate.  Must be a fake.

Actually congrats on the find.  Those are beautiful.

And hard to come by in one piece.

[doushantuo]

High "drool factor".

Those are really giant agnostids, BTW. 

[Fossildude19]

Way to go, Don!   

[FossilDAWG]

15 minutes ago, doushantuo said:

High "drool factor".

Those are really giant agnostids,BTW

Oops, I did forget to include a scale didn't I.  The individual trilobites are about 2 mm, and the distance between the pair and the individual in the second photo is 1.49 cm.  The view in the top photo is about 1.75 cm wide.  All four trilobites fit comfortably within a 2 x 2 cm square.  So in fact they are quite tiny.  But I still like them very much.

 

Don

[doushantuo]

I posted this yesterday (or rather,part of it); Maybe you like it,and maybe not.

 

[ynot]

Nice plate.

[MeargleSchmeargl]

8 hours ago, FossilDAWG said:

I was splitting up some Conasauga Formation shale from the Chatsworth area exposure @Nimravis and @MeargleSchmearglhave been posting about recently.  This was material I brought back 2 or 3 years ago and have had sitting around.  I found numerous specimens of the usual Aphelaspis the site is noted for.  Then I split a small piece and here's what popped out:

 

Four complete Agnostus inexpectans agnostid trilobites!!  Talk about "inexpected", it's hard to find one of these complete much less four on the same piece of shale.  

Some other views:

 

Don

 

 

No Agnostids from me yet, but that gives me all the more reason to keep going back!

[izak_]

Very nice! 

[Kane]

These are quite lovely, Don! To find four on one piece is a real coup (I haven't even found one yet! ). 

[Miocene_Mason]

Nice!

[Nimravis]

@FossilDAWG Congrats-That is a rare occurrence for that matrix and those are beautiful- I have found many 1/2 pieces and only 2 complete and they were on separate pieces. My most recent was next to a baby Aphelaspis- see below.

 

@Monica , @Peat Burns and @Shellseeker - keep an eye out.

 

Btw- the scale cube is 1 CM.

 

[Pagurus]

 Nice find, Don!  Congrats. 

[Peat Burns]

2 hours ago, Nimravis said:

@FossilDAWG Congrats-That is a rare occurrence for that matrix and those are beautiful- I have found many 1/2 pieces and only 2 complete and they were on separate pieces. My most recent was next to a baby Aphelaspis- see below.

 

@Monica , @Peat Burns and @Shellseeker - keep an eye out.

 

Btw- the scale cube is 1 CM.

 

I have my fingers, toes, and eyes crossed, Ralph!

[FossilDAWG]

What I'd really like to find next is a complete Glyptagnostis. That's the really wrinkly agnostid. I have a couple of pieces but nothing complete. If anyone finds one I hope they post it.

 

Don

[doushantuo]

you mean?

[Darktooth]

Awesome find! Congratulations! 

[Nimravis]

42 minutes ago, FossilDAWG said:

What I'd really like to find next is a complete Glyptagnostis. That's the really wrinkly agnostid. I have a couple of pieces but nothing complete. If anyone finds one I hope they post it.

 

Don

That would be nice - I also like this partial big boy that I found-“Eugonocare”. It’ the only one that I have ever found.

 

[Monica]

@Nimravis

Thanks for the heads-up - now I'm even more excited about cracking into those rocks!!!

 

@minnbuckeye and @Pagurus - maybe you'll find some nice little surprises, too! 

[Pagurus]

1 hour ago, Monica said:

@Nimravis

Thanks for the heads-up - now I'm even more excited about cracking into those rocks!!!

 

@minnbuckeye and @Pagurus - maybe you'll find some nice little surprises, too! 

 

Thanks again for your generosity, Monica (and Ralph, too.)  I hope we all have good luck. I once had a rabbit's foot for good luck, though it wasn't too lucky for the rabbit.

[piranha]

Barrandagnostus inexpectans is the most recent classification.

 

 

Naimark, E.B., & Pegel, T.V. (2017)

Revision of the Cambrian Agnostina (Trilobita?) from Russia. 

Paleontological Journal, 51(11):1167-1248   PDF LINK

 

"The morphology of the specimens assigned to B. barrandei resembles the diagnosis of Innitagnostus; therefore, Petrunina and Gabova suggested Innitagnostus was a junior synonym of Barrandagnostus, invoking principle of nomenclatural priority.  Here we distinguish these genera by the shape of the preglabellar furrow whether complete in Barrandagnostus or incomplete or absent in Innitagnostus.  According to this difference, I. inexpectans (Kobayashi, 1938) should be assigned to Barrandagnostus."

 

 

There have been numerous publications after Schwimmer & Montante 2012, that still assign Innitagnostus inexpectans.

The following papers among others, have continued to assign this species as Innitagnostus inexpectans, n. gen. Öpik 1967.

 

Choi, D.K., Lee, J.G., Lee, S.B., Park, T.Y.S., & Hong, P.S. (2016)

Trilobite biostratigraphy of the Lower Paleozoic (Cambrian–Ordovician) Joseon Supergroup, Taebaeksan Basin, Korea.

Acta Geologica Sinica, 90(6):1976-1999

 

Hally, L.A., & Paterson, J.R. (2014)

Biodiversity, biofacies and biogeography of middle Cambrian (Series 3) arthropods (Trilobita and Agnostida) on the East Gondwana margin.

Gondwana Research, 26(2):654-674

 

Westrop, S.R., & Eoff, J.D. (2012)

Late Cambrian (Furongian; Paibian, Steptoean) Agnostoid Arthropods from the Cow Head Group, Western Newfoundland.

Journal of Paleontology, 86(2):201-237

 

Peng, S., Babcock, L.E., Zuo, J., Zhu, X., Lin, H., Yang, X., Qi, Y.,  Bagnoli, G., & Wang, L. (2012)

Global standard stratotype-section and point (GSSP) for the base of the Jiangshanian Stage (Cambrian: Furongian) at Duibian, Jiangshan, Zhejiang, southeast China.

Episodes, 35(4):462-477

[Plax]

21 hours ago, FossilDAWG said:

What I'd really like to find next is a complete Glyptagnostis. That's the really wrinkly agnostid. I have a couple of pieces but nothing complete. If anyone finds one I hope they post it.

 

Don

I posted a pic earlier but must have misspelled the name it doesn't pick up in a search. Am thinking it was in a Nimravis post.

[Pagurus]

11 hours ago, Plax said:

I posted a pic earlier but must have misspelled the name it doesn't pick up in a search. Am thinking it was in a Nimravis post.

 

Perhaps this post?  Wonderful finds in this matrix!

[Wrangellian]

Nice find! They do sound tiny, usually I expect 5-8mm or so, but good things come in small packages.