Cambrian - Carboniferous Spike Headed Trilobites

[pefty]

On 12/26/2012 at 3:12 PM, piranha said:

One more spike-headed participant to add to this thread. Phacops is easily one of the most recognized and iconic standard-bearers of all Trilobita and also has a piercing presence in this category. Echinophacops is found in the Devonian (late Emsian) Zhusileng Formation of Inner Mongolia. There are a handful of phacopid trilobites with small genal and axial spines but this one beats them all with 17 spines sprouting from the glabella and lateral margins of the cephalon. The Greek word 'Echinos' for this spiny genus is certainly on point!

I'm curious what the pygidium of such a trilobite looks like.... Any figures of that available? 

[piranha]

 

figures from:

 

Zhou, Z.Q. 1983
Echinophacops, A New Genus of the Subfamily Phacopinae. Acta Palaeontologica Sinica, 22(6):642-650

 

Zhou, Z.Q., Campbell, K.S.W. 1990
Devonian Phacopacean Trilobites from the Zhusilenghaierhan Region, Ejin Qi, Western Inner Mongolia, China. Palaeontographica Abteilung A, 214:57-77

[pefty]

Fascinating, especially those two "fangs" on the underside of the cephalon. I thought that antennae typically emerged from the hypostome, so........what are those? Weird.

[piranha]

from Zhou 1983:

 

"Some well-preserved specimens of Echinophacops gen. nov. clearly show ventral structures. On the ventral side of cephalon, the doublure of genal regions, but lacking or extremely feeble on the ventral surface of glabella; no traces of pits are found at the bottom of vincular furrow."

 

[pefty]

On 12/21/2012 at 7:34 PM, piranha said:

Just to follow up on this topic I found another similarly spike-headed marvel. The fascinating tidbit is this genus is a Carboniferous example. Typically the trilobites from the last three surviving families of the Carboniferous to Permian extinction are rather nondescript by comparison. Then with one last triumphant display, Namuropyge is the final holdout of the spiny menagerie of trilobites. Namuropyge has worldwide distribution across Asia, Australia, Europe and the USA. Namuropyge cuyahogae is my favorite of this bunch with three comb-like spines on each of its genal spines! For the Midwest collectors who are interested, the figured species of N. cuyahogae can be found in the Cuyahoga Shales of Ohio and the Chouteau LS of Missouri.

Piranha, do you know if those bottom four are N. cuyahogae and if so what articles they are from? Thanks. 
 

Also I noticed that since the holotype of N. cuyahogae was lost in a fire, a new subgenus and species have been erected to capture the Ohio and presumably Missouri Namuropyge specimens: 

Namuropyge (Cuyapyge) brooksi. 

https://tinyurl.com/cuyapyge

[piranha]

1 hour ago, pefty said:

do you know if those bottom four are N. cuyahogae and if so what articles they are from?

 

from left to right:

 

Namuropyge uniserialis
Namuropyge uniserialis
Namuropyge australis
Namuropyge acanthina

 

Hahn, G., Hahn, R. 1996

Die Trilobiten-Taxa des Karbons und Perms: 2. Brachymetopidae.

[The Trilobite Taxa of the Carboniferous and Permian: 2. Brachymetopidae.]

Courier Forschungsinstitut Senckenberg, 195:1-242

[pefty]

10 hours ago, piranha said:

 

from left to right:

 

Namuropyge uniserialis
Namuropyge uniserialis
Namuropyge australis
Namuropyge acanthina

 

Hahn, G., Hahn, R. 1996

Die Trilobiten-Taxa des Karbons und Perms: 2. Brachymetopidae.

[The Trilobite Taxa of the Carboniferous and Permian: 2. Brachymetopidae.]

Courier Forschungsinstitut Senckenberg, 195:1-242

 

Thank you!

 

Hahn and Hahn 1996 is a paper I would LOVE to get my hands on if you happen to know where I could access a softcopy....

[doushantuo]

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