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aek

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This morning I made a trip to a local spot. Wenlockian.

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Gravicalymene celebra, measures 4cm

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This one was difficult to work with, as dolostone always is.  Ommokris obex cephalon, which turned out to be partial, and a small ventral calymene. The arrow points to the tongue-like protuberance which I was able to extract in one piece and glue back on, giving this trilobite a gargoylesque appearance.

 

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And last but not least, a mystery find...

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39 minutes ago, aek said:

...This one was difficult to work with, as dolostone always is.  Ommokris obex cephalon,...

...The arrow points to the tongue-like protuberance which I was able to extract in one piece and glue back on, giving this trilobite a gargoylesque appearance.

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Well done putting this puzzle back together.  Congrats on your continued success with some great Silurian trilobites! :drool:

 

Here are figures of the unicorn dalmanitid from Holloway 1981:

 

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Holloway, D.J. 1981

Silurian Dalmanitacean Trilobites from North America and the Origins of the Dalmanitinae and Synphoriinae. Palaeontology, 24(4):695-731  PDF LINK

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you are doing some great prepwork there :) congrats 

growing old is mandatory but growing up is optional.

 

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Very cool! I am impressed with your prepping, I am still sitting on 4 calymene trilobites in dolomite that I haven't worked up the motivation to really try and bust out yet. Yours looks so clean, and the reassembly of the bizarre other trilobite turned out great as well. :thumbsu:

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Another find from this locality. I was able to very carefully reattach  the eye stalk as seen below, but I'm not sure as to species ID?? @piranha

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 hypostome

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Encrinurus egani

 

image from: AMNH

 

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text from:

 

Holloway, D.J. 1980

Middle Silurian Trilobites from Arkansas and Oklahoma, U.S.A.

Palaeontographica Abt.A, 170:1-85

 

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@ynot @RJB Thanks!

An additional find from this spot (which I think is now "tapped out"unfortunately..) A rare Ceratocephala goniata cephalon with thoracic segments. It is interesting to note in my old paleontological books, the cephalon is oriented backwards because (I'm assuming) nobody had yet found a complete specimen!

 

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4 hours ago, aek said:

An additional find from this spot (which I think is now "tapped out"unfortunately..) A rare Ceratocephala goniata cephalon with thoracic segments. It is interesting to note in my old paleontological books, the cephalon is oriented backwards because (I'm assuming) nobody had yet found a complete specimen!

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In the original description, Warder 1838 is the culprit with the upside down cephalon.  Eventually, Vogdes 1876 was the first to discover this incorrect description.  Unfortunately, Armstrong & Armstrong 1962 did not get the memo and followed suit with another upside down illustration.  Although IFNA does not give a precise description of the Weller 1907 figure, Weller described it accurately as the anterior view of a nearly complete cephalon.  What a mess! :P  You are on a hot streak with these unusual Silurian trilobites.  Looking forward to a Deiphon americanus in the very near future! :o:ninja:

 

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Warder, J.A. 1838

MISCELLANIES. 4. New Trilobites: Ceratocephala goniata.

American Journal of Science, 1st series, 34(2):377-379

 

Vogdes, A.W. 1876

Notes on the Genera Acidaspis, Murchison; Odontopleura, Emmerich; and Ceratocephala, Warder.

Proceedings of the Academy of Natural Sciences of Philadelphia, 2nd series, 20:138-141

 

Weller, S. 1907

The Paleontology of the Niagaran Limestone in the Chicago Area: The Trilobita.

Natural History Survey, Chicago Academy of Sciences Bulletin, 4(2):163-281

 

Armstrong, C., Armstrong, P. 1962

Trilobites of the Chicago Region.

Mid America Paleontology Society, 59 pp.

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Thanks @piranha such a strange looking  creature. It's  easy to see how Armstrong &Armstrong thought this trilobite could be blind, as the eyes are not apparent.

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