Wrangellian Posted December 19, 2012 Share Posted December 19, 2012 I just acquired these trilos from China, just wanted to make sure the names/locations are correct as I have seen it vary between sellers... Ductina vietnamica - Devonian: Famennian (according to Sepkoski) - Mountains of W. Guangxi, China -also curious what those little spike or cone shaped bits are that surround the trilo and in fact fill the shale in the one piece at least! (trilo is about 34mm long) Coronocephalina jastrowi, Silurian: Wenlockian (Sepkoski) - Mtns of W. Hunan, China (have also seen Hubei and Henan, and the genus name Coronocephalus but maybe that's for the other species) ?? - length ~5.5cm Link to comment Share on other sites More sharing options...
Sinopaleus Posted December 19, 2012 Share Posted December 19, 2012 I just acquired these trilos from China, just wanted to make sure the names/locations are correct as I have seen it vary between sellers... Ductina vietnamica - Devonian: Famennian (according to Sepkoski) - Mountains of W. Guangxi, China -also curious what those little spike or cone shaped bits are that surround the trilo and in fact fill the shale in the one piece at least! (trilo is about 34mm long) Coronocephalina jastrowi, Silurian: Wenlockian (Sepkoski) - Mtns of W. Hunan, China (have also seen Hubei and Henan, and the genus name Coronocephalus but maybe that's for the other species) ?? - length ~5.5cm Good stuff! All locations are correct, and species is too. Coronocephalus has a lot of species, and to me a lot of them look quite similar, which makes it hard for me to distinguish one from another... I'll leave the I.Ding to Scott Nice trilobites! Link to comment Share on other sites More sharing options...
FossilDAWG Posted December 19, 2012 Share Posted December 19, 2012 The cone-shaped fossils are hyoliths, a group of uncertain but probably molluscan affinities, that are common in some Cambrian formations and much rarer later on in the Paleozoic. Don 1 Link to comment Share on other sites More sharing options...
piranha Posted December 19, 2012 Share Posted December 19, 2012 Hi Eirc, One correction worth noting is the species name Coronocephalus jastrowi is not valid. Although it is commonly labeled as C. jastrowi among the trilobite dealers, that name has never been officially assigned to any of the Coronocephalus species from China. The Hunan species that matches best is: Coronocephalus gaoluoensis. Since these are rarely found intact I have attached a few complete examples that showcase the morphology of spikes and spines that decorate this bizarre trilobite. 1 Link to comment Share on other sites More sharing options...
Wrangellian Posted December 19, 2012 Author Share Posted December 19, 2012 (edited) Thanks everybody.. I saw that name gaoluoensis online but wasn't sure if these were the same (sure looked similar but as Henry says they all do!) So it's Coronocephalus, not -ina? Don, I thought of hyoliths, but wasn't sure because they are very small and numerous. It's a more interesting piece now! Actually I bought this example partly because of those - wanted to find out. I just noticed my Corono has a poor repair on it... hope I can detach it with some acetone and redo it.. Edited December 19, 2012 by Wrangellian Link to comment Share on other sites More sharing options...
piranha Posted December 20, 2012 Share Posted December 20, 2012 ...So it's Coronocephalus, not -ina?... Correct and further research shows that Coronocephalina is actually assigned as a sub-genus of Senticucullus which is also in the subfamily Coronocephalinae. I thought it was worth mentioning considering the incredible array of cephalic spikes on Senticucullus. 1 Link to comment Share on other sites More sharing options...
Missourian Posted December 20, 2012 Share Posted December 20, 2012 Cool bugs. The hyoliths in the first are a nice bonus. Context is critical. Link to comment Share on other sites More sharing options...
Wrangellian Posted December 20, 2012 Author Share Posted December 20, 2012 Thanks, it's nice to have the correct info for my labels. Yes I'm glad I bought that one.. usually when I buy or find something that might be a _____ it usually turns out not to be! Link to comment Share on other sites More sharing options...
Bullsnake Posted December 20, 2012 Share Posted December 20, 2012 Really nice aquisition! Steve Link to comment Share on other sites More sharing options...
Sinopaleus Posted December 20, 2012 Share Posted December 20, 2012 Correct and further research shows that Coronocephalina is actually assigned as a sub-genus of Senticucullus which is also in the subfamily Coronocephalinae. I thought it was worth mentioning considering the incredible array of cephalic spikes on Senticucullus. Oh wow. Link to comment Share on other sites More sharing options...
Wrangellian Posted December 20, 2012 Author Share Posted December 20, 2012 Trilobites are a fascinating varied group.. I have always thought so but I'm finding it easier than I used to think to acquire specimens that I would think are not too common... These Ductias are pretty common on the market, and I see my other specimen (not pictured) has hyoliths around it too.. some are pretty tiny, like about 1mm long and a fraction as wide. Some appear to be segmented. I don't know if I'd be able to get very good pics of them! I was also interested to learn these are Famennian - around the time of the (extended) Devonian Extinction. Link to comment Share on other sites More sharing options...
Shamalama Posted December 20, 2012 Share Posted December 20, 2012 The cone-shaped fossils are hyoliths, a group of uncertain but probably molluscan affinities, that are common in some Cambrian formations and much rarer later on in the Paleozoic. Don Would they be Hyolithids or Styliolinids (which are closer related to Tentaculites)? The latter is very common in Devonian rocks. I posted an example on my blog from Arkona. -Dave __________________________________________________ Geologists on the whole are inconsistent drivers. When a roadcut presents itself, they tend to lurch and weave. To them, the roadcut is a portal, a fragment of a regional story, a proscenium arch that leads their imaginations into the earth and through the surrounding terrain. - John McPheeIf I'm going to drive safely, I can't do geology. - John McPheeCheck out my Blog for more fossils I've found: http://viewsofthemahantango.blogspot.com/ Link to comment Share on other sites More sharing options...
Sinopaleus Posted December 20, 2012 Share Posted December 20, 2012 Trilobites are a fascinating varied group.. I have always thought so but I'm finding it easier than I used to think to acquire specimens that I would think are not too common... These Ductias are pretty common on the market, and I see my other specimen (not pictured) has hyoliths around it too.. some are pretty tiny, like about 1mm long and a fraction as wide. Some appear to be segmented. I don't know if I'd be able to get very good pics of them! I was also interested to learn these are Famennian - around the time of the (extended) Devonian Extinction. One of the very last of the Phacopidae lineage Link to comment Share on other sites More sharing options...
trilobiteruss Posted December 20, 2012 Share Posted December 20, 2012 Correct and further research shows that Coronocephalina is actually assigned as a sub-genus of Senticucullus which is also in the subfamily Coronocephalinae. I thought it was worth mentioning considering the incredible array of cephalic spikes on Senticucullus. Wow Scott, those are awesome with the spikes! Link to comment Share on other sites More sharing options...
Wrangellian Posted December 21, 2012 Author Share Posted December 21, 2012 Would they be Hyolithids or Styliolinids (which are closer related to Tentaculites)? The latter is very common in Devonian rocks. I posted an example on my blog from Arkona. Sorry Dave, missed your post til now... Interesting idea, I have never heard of Cricoconarids before - I wonder if they are related to tentaculitids if the ones of my specimen are a mix of segmented (ringed, ridged?) and smooth, and within the same size range (small). Link to comment Share on other sites More sharing options...
ElToro Posted November 19, 2015 Share Posted November 19, 2015 Trilobites are a fascinating varied group.. I have always thought so but I'm finding it easier than I used to think to acquire specimens that I would think are not too common... These Ductias are pretty common on the market, and I see my other specimen (not pictured) has hyoliths around it too.. some are pretty tiny, like about 1mm long and a fraction as wide. Some appear to be segmented. I don't know if I'd be able to get very good pics of them! I was also interested to learn these are Famennian - around the time of the (extended) Devonian Extinction. Wow. I google Coronocephalus and this comes up. Wrangellian, we meet in the strangest places... Onhua has a nice specimen for less than $5 so I'm bidding. I figure it would be cool for my first trilo. "That belongs in a museum!" - Indiana Jones Link to comment Share on other sites More sharing options...
ElToro Posted November 19, 2015 Share Posted November 19, 2015 I remember looking at them in Paleo class, but we only had a couple pygidiums, no thorax. "That belongs in a museum!" - Indiana Jones Link to comment Share on other sites More sharing options...
Wrangellian Posted November 19, 2015 Author Share Posted November 19, 2015 You could probably find one with at least a partial head intact.. but you can't beat $5 I guess. Link to comment Share on other sites More sharing options...
ElToro Posted November 19, 2015 Share Posted November 19, 2015 Yea, I didn't really look. I just saw it and the current bid is around $2. I am sensing that if I wait til the last moment I can get it for around $5 and its free shipping. Many of these don't have heads. Are they rare? "That belongs in a museum!" - Indiana Jones Link to comment Share on other sites More sharing options...
Wrangellian Posted November 20, 2015 Author Share Posted November 20, 2015 I've seen quite a few without heads, they must be pretty common, but the ones with heads (esp. w/full front margins) are rarer of course.. Link to comment Share on other sites More sharing options...
ElToro Posted November 20, 2015 Share Posted November 20, 2015 Yea, I had a look and there are a few whole ones for around $20. What u think of this silver ring I scored for $4? Never seen anything like it, and I love it! "That belongs in a museum!" - Indiana Jones Link to comment Share on other sites More sharing options...
FossilDAWG Posted November 20, 2015 Share Posted November 20, 2015 Would they be Hyolithids or Styliolinids (which are closer related to Tentaculites)? The latter is very common in Devonian rocks. I posted an example on my blog from Arkona. Now that this thread has been resurrected, I looked again and I think Dave was correct on this. I had mistakenly thought the fossils in question were Cambrian for some reason, but styliolinids are a better fit for a Late Devonian fossil. They are both rather nondescript cone-shaped fossils, quite similar in appearance unless they are very well preserved. Don 1 Link to comment Share on other sites More sharing options...
Wrangellian Posted November 21, 2015 Author Share Posted November 21, 2015 Thanks Don, So how are styliolinids related to cricoconarids... are the styliolinids non-tentaculitid cricoconarids? Link to comment Share on other sites More sharing options...
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