gturner333 Posted November 16, 2015 Share Posted November 16, 2015 I found these ammonites and brachiopods at Jacksboro, Texas, which is Pennsylvanian - Graham Formation. The brachs look like Punctospirifer, but with more detail on the folds. I really don't know about the ammonites with their ribs so close together. Any ideas? Link to comment Share on other sites More sharing options...
DPS Ammonite Posted November 16, 2015 Share Posted November 16, 2015 Gary, Nice brachs and ammonites. Jacksboro is amazing. The brachiopods are Punctospirifer kentuckyensis. See this website: http://viewsofthemahantango.blogspot.com/2012/12/punctospirifer-kentuckeyensis-from-texas.html Cheers, John My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
ZiggieCie Posted November 16, 2015 Share Posted November 16, 2015 Nice find, thx for sharing. Link to comment Share on other sites More sharing options...
gturner333 Posted November 16, 2015 Author Share Posted November 16, 2015 Thanks. I was soooo close. Now, hopefully someone can help with the ammonite. Link to comment Share on other sites More sharing options...
Herb Posted November 16, 2015 Share Posted November 16, 2015 Polaricyclus "Absence of evidence is not evidence of absence"_ Carl Sagen No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go. " I think, therefore I collect fossils." _ Me "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes "can't we all just get along?" Jack Nicholson from Mars Attacks Link to comment Share on other sites More sharing options...
DPS Ammonite Posted November 16, 2015 Share Posted November 16, 2015 Gary, Can you take a photo of the sutures to help with an ID. On the top part of the lower right one it looks like sutures are visible. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
gturner333 Posted November 16, 2015 Author Share Posted November 16, 2015 I'll try, but the computer i use with my microscope is flaky. These do look like the Polaricyclus, but they seem to be associated with Mississippian period more than Pennsylvanian. Did they extend into the Pennsylvanian? Link to comment Share on other sites More sharing options...
Ridgehiker Posted November 16, 2015 Share Posted November 16, 2015 Thanks. I was soooo close. Now, hopefully someone can help with the ammonite. Nice specimens. Thanks for sharing. If it is Upper Carboniferous it is a goniatite and not an ammonite Link to comment Share on other sites More sharing options...
BobWill Posted November 16, 2015 Share Posted November 16, 2015 (edited) P. kentuckyensis is indeed found at Jaxbro. It would be an addition to the faunal list if those ammonoids were Polaricyculus though, as well as a 45.3 million year extension of their known age range. I think John's suggestion is your only hope. If you can find a spot where some of an internal mold is showing through for a look at the sutures since that's what's shown in most references. Lance Hall has the bottom one on his website but he labels it unknown. See the second image on his Pennsylvanian ammonoids page. Did you place them like that to look like two ducks having a chat? Edited November 16, 2015 by BobWill Link to comment Share on other sites More sharing options...
Wrangellian Posted November 16, 2015 Share Posted November 16, 2015 Ha! I didn't see the ducks until you mentioned it. Nice specimens, GT. Link to comment Share on other sites More sharing options...
gturner333 Posted November 18, 2015 Author Share Posted November 18, 2015 I had to replace my computer, but seem to be back into business now. In looking at these ducks - I mean fossils - it seems that there may be two different species here (earlier fossil placement in the picture was entirely accidental). They both have close ribbing and the same type of sutures, but the overall body shapes are a little different. Could one be a Polaricyculus and the other something else? Link to comment Share on other sites More sharing options...
gturner333 Posted November 18, 2015 Author Share Posted November 18, 2015 i neglected to mention earlier that the hash marks are 1mm. Link to comment Share on other sites More sharing options...
BobWill Posted November 18, 2015 Share Posted November 18, 2015 The second one appears to be Imitoceras sp. but I haven't found the first one yet. It's not Polaricyclus though. Not only are they older they also have constrictions we don't see here. Seeing the ventral view it has the same shape as both Eoasianites sp. and Vidrioceras sp. but the sutures don't match either one so the search is still on. Link to comment Share on other sites More sharing options...
gturner333 Posted November 18, 2015 Author Share Posted November 18, 2015 Bob, I was looking in the "DPS Pennsylvanian Fossils of North Texas" book and it said that Imitoceras lacked ribbing. Maybe they were just talking about the example in the book. But the one above definitely has very detailed ribbing. Do you have some other info that identifies this as a Imitoceras? I appreciate your help on this. Link to comment Share on other sites More sharing options...
BobWill Posted November 18, 2015 Share Posted November 18, 2015 If these are ribs that are barely visible on mine then they could be described as "faint" and could be easily missed. The treatise doesn't mention their absence or presence. If you're right then we're still looking for both. Link to comment Share on other sites More sharing options...
Herb Posted November 18, 2015 Share Posted November 18, 2015 the 3rd one looks like Eoasianites sp. Maybe some new species here? "Absence of evidence is not evidence of absence"_ Carl Sagen No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go. " I think, therefore I collect fossils." _ Me "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes "can't we all just get along?" Jack Nicholson from Mars Attacks Link to comment Share on other sites More sharing options...
bone2stone Posted November 18, 2015 Share Posted November 18, 2015 the 3rd one looks like Eoasianites sp. Maybe some new species here? Now wouldn't that be something a new species... Nice finds and thanks for the scale info. That was my first question that I did not get to before it was answered. The coloring is beautiful. Link to comment Share on other sites More sharing options...
gturner333 Posted November 18, 2015 Author Share Posted November 18, 2015 The 3rd picture is the edge view of the middle picture, which shows (barely) the sutures. Link to comment Share on other sites More sharing options...
BobWill Posted November 18, 2015 Share Posted November 18, 2015 Eoasianites sp. is too globular for the second one but for that reason I considered it for the first one except that yours is a little more involute and there aren't enough saddles and lobes on the sutures. We help from someone with more than a just couple of rusty old books Link to comment Share on other sites More sharing options...
gturner333 Posted November 19, 2015 Author Share Posted November 19, 2015 I agree. Does anyone know an expert in Pennsylvanian ammonoids? Link to comment Share on other sites More sharing options...
DPS Ammonite Posted November 19, 2015 Share Posted November 19, 2015 (edited) I wonder if this article might help. Anyone have a copy? Miller's "Ammonoids of the Pennsylvanian Finis shale of Texas", Journal of Paleontology, March 1950, v. 24, p. 185-218 Edited November 19, 2015 by DPS Ammonite My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
gturner333 Posted November 25, 2015 Author Share Posted November 25, 2015 Well, after a search that led me to TFF, California, Oxford, then Ohio University, I think I have found an answer. Dr. Royal Mapes of Ohio University was kind enough to look at these and here is what he wrote back: "Hi Gary, On the two larger specimens in one photo. The only ribbed goniatite in the Finis (which I have collected numerous times) with ribs that more-or-less cover the shell like these two specimens is Neodimorphoceras. The species is probably N. texanum, but it is too juvenile to tell for sure. The smaller specimen is almost certainly a juvenile Gonioloboceras. That goniatite genus has a lateral ribbed conch in diameters of less than about 5 mm. It loses the ribs as it grows and by about 10 mm it has lost them and the conch is becoming more discoidal. Also the genus at the diameter of your specimen has very shallow ventral lobed suture at the marginal siphuncle. Neodimorphoceras is moderately rare in the Finis (and elsewhere) and is easily confused with Gonioloboceras which is very common in the Finis. The way you tell the difference in the mature forms is that the ventral lobe is subdivided in the Neodimorphoceras and it is not in the Gonioloboceras; both at maturity have smooth discoidal conchs. Hope this helps, Royal" Dr. Mapes' bio can be found on the web. I think I will go with this as the identification. 1 Link to comment Share on other sites More sharing options...
gturner333 Posted November 25, 2015 Author Share Posted November 25, 2015 This is strange, I just posted something on this topic, TFF accepted it, but I do not see it in the thread. I'll try again. After a search that took me from TFF, to California, Oxford, then Ohio University, I think I have found an answer. Dr. Royal Mapes of Ohio University (bio is online) was kind enough to look over my pictures and this is what he had to say: "Hi Gary, On the two larger specimens in one photo. The only ribbed goniatite in the Finis (which I have collected numerous times) with ribs that more-or-less cover the shell like these two specimens is Neodimorphoceras. The species is probably N. texanum, but it is too juvenile to tell for sure. The smaller specimen is almost certainly a juvenile Gonioloboceras. That goniatite genus has a lateral ribbed conch in diameters of less than about 5 mm. It loses the ribs as it grows and by about 10 mm it has lost them and the conch is becoming more discoidal. Also the genus at the diameter of your specimen has very shallow ventral lobed suture at the marginal siphuncle. Neodimorphoceras is moderately rare in the Finis (and elsewhere) and is easily confused with Gonioloboceras which is very common in the Finis. The way you tell the difference in the mature forms is that the ventral lobe is subdivided in the Neodimorphoceras and it is not in the Gonioloboceras; both at maturity have smooth discoidal conchs. Hope this helps, Royal" I think I will go with this for an ID. Link to comment Share on other sites More sharing options...
gturner333 Posted November 26, 2015 Author Share Posted November 26, 2015 DPS Ammonite, You can find a copy of Miller and Down's "Ammonoids of the Pennsylvanian Finis shale of Texas", Journal of Paleontology, March 1950, v. 24, p. 185-218 on jstor.org. And yes, it shows a perfect example of my fossil above as being Neodimorphoceras texanum at one of its stages of growth. Check it out. And your contact for help didn't directly pan out, but he gave me Dr. Mapes' name. So it all worked out in the long run. Link to comment Share on other sites More sharing options...
DPS Ammonite Posted November 26, 2015 Share Posted November 26, 2015 Thanks Gary, A good reference from a professional to help ID a fossil is a valuable thing. I tell my paleontologist contacts to look at The Fossil Forum if they want to do some pro bono work. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
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