pleecan Posted July 16, 2012 Share Posted July 16, 2012 (edited) Alfred Newnham found this crinoid fossil and is seeking an ID: Edited July 17, 2012 by pleecan Link to comment Share on other sites More sharing options...
thanatocoenosis Posted July 16, 2012 Share Posted July 16, 2012 (edited) I have an ideal, but first, up-load a high resolution photo of the calyx. EDIT: It appears to be a cladid. Is it dicyclic? Edited July 16, 2012 by thanatocoenosis 2012 NCAA Collegiate Round Ball Champs; and in '98, '96, '78, 58, '51, '49, and '48, too. Link to comment Share on other sites More sharing options...
pleecan Posted July 16, 2012 Author Share Posted July 16, 2012 I have an ideal, but first, up-load a high resolution photo of the calyx. EDIT: It appears to be a cladid. Is it dicyclic? Unfortunately I do not have the specimen.... That will have to wait as I was just visiting when I took those pictures with my camera. My next visit in the fall , Alf will give me the specimen to imaged on my setup capable of 10 micron resolution in reflective light.... the ROM has also requested pictures also of the calyx. Link to comment Share on other sites More sharing options...
FossilDAWG Posted July 16, 2012 Share Posted July 16, 2012 Seems to be a good specimen of Iocrinus subcrassus. I have collected simialr specimens from the upper part of the Lindsey Formation (used to be called the Cobourg) near Ottawa, and the species occurs in New York State as well as in the Cincinnatti area, so it's not surprising that it would be found in Prince Edward County. Don Link to comment Share on other sites More sharing options...
Caleb Posted July 16, 2012 Share Posted July 16, 2012 I'm not sure what kind it is, but here's a link to the discription of Iocrinus trentonensis. Caleb Midwestpaleo.com Link to comment Share on other sites More sharing options...
pleecan Posted July 16, 2012 Author Share Posted July 16, 2012 (edited) Seems to be a good specimen of Iocrinus subcrassus. I have collected simialr specimens from the upper part of the Lindsey Formation (used to be called the Cobourg) near Ottawa, and the species occurs in New York State as well as in the Cincinnatti area, so it's not surprising that it would be found in Prince Edward County. Don Thanks Don... Bill Hessin also id as Iocrinus.... PL Edited July 16, 2012 by pleecan Link to comment Share on other sites More sharing options...
pleecan Posted July 16, 2012 Author Share Posted July 16, 2012 I'm not sure what kind it is, but here's a link to the discription of Iocrinus trentonensis. Thanks Caleb for he link! PL Link to comment Share on other sites More sharing options...
ssuntok Posted July 16, 2012 Share Posted July 16, 2012 I'd be inclined to go with whatever Bill Hessin says Steve Suntok Link to comment Share on other sites More sharing options...
thanatocoenosis Posted July 16, 2012 Share Posted July 16, 2012 Seems to be a good specimen of Iocrinus subcrassus. I have collected simialr specimens from the upper part of the Lindsey Formation (used to be called the Cobourg) near Ottawa, and the species occurs in New York State as well as in the Cincinnatti area, so it's not surprising that it would be found in Prince Edward County. Don Could be, but on such poor example of photography, why? From the photo, I couldn't determine if it had infra-basals or not. Please elaborate. 2012 NCAA Collegiate Round Ball Champs; and in '98, '96, '78, 58, '51, '49, and '48, too. Link to comment Share on other sites More sharing options...
pleecan Posted July 16, 2012 Author Share Posted July 16, 2012 Could be, but on such poor example of photography, why? From the photo, I couldn't determine if it had infra-basals or not. Please elaborate. Lets be civilized about it. The photo is the best I could do given the moment.... I don't truck my equipment with me. You just got to wait. I did not use a tripod and the camera system is about $1000. The object is tiny and hard to photograph. I also resent the comment as being a poor example of photography! I don't need to show you guys anything with comments like that! So bear in mind I carry +30yrs of optics know how! PL Link to comment Share on other sites More sharing options...
pleecan Posted July 16, 2012 Author Share Posted July 16, 2012 (edited) I'd be inclined to go with whatever Bill Hessin says Actually Steve, I got my fossil start from Bill Hessin at Colborne quarry..... many yrs ago. He taught me lots.... in the early days. Edited July 16, 2012 by pleecan Link to comment Share on other sites More sharing options...
pleecan Posted July 17, 2012 Author Share Posted July 17, 2012 This also could be an undescribed crinoid.... has not been ruled out.... Link to comment Share on other sites More sharing options...
Crinoid Queen Posted July 17, 2012 Share Posted July 17, 2012 Very nice little crinoid! Supper CUTE! Link to comment Share on other sites More sharing options...
pleecan Posted July 17, 2012 Author Share Posted July 17, 2012 If anything Peter, your photos are crisp, high magnification and carried out in different approaches, under solutions, polarized and optimum lighting conditions. I appreciate these were not controlled conditions. Maybe thanatocoenosis misstated his meaning. It is hard to find features. We can wait for the scrutiny of your photo lab. Alfred has a good eye for the tiny. Alfred home is only 2 blocks from the quarry.... that has been in operation for 30 odd yrs.... he tells me this is the second crinoid calyx that he has found in decade he has been hunting in this quarry... it tells me that crinoid specimen is rare.... he also told me that he donated/gave/traded a complete crinoid with calyx stalk and roots to some one in the USA.... too bad it did not remain in Ontario.... about 3o miles away there is another quarry in the Ordovician that has kimberlite pipes.... so there is a possible volcanic component.... Link to comment Share on other sites More sharing options...
FossilDAWG Posted July 17, 2012 Share Posted July 17, 2012 (edited) Could be, but on such poor example of photography, why? From the photo, I couldn't determine if it had infra-basals or not. Please elaborate. You are of course correct to question why I would make such a definative ID. I would hope that Peter would take my ID as a hypothesis, and look up a proper description to confirm or refute the identification.In this case, I know the geology of the area, and spent several years becoming familiar with the local Ordovician echinoderm fauna. In this case, the arms lack pinnules, which excludes Glyptocrinus, Pycnocrinus, Archaeocrinus, Periglyptocrinus, and other less common taxa. Of course the cup shape and ornamentation is totally different in those genera too. Amongst the non-pinnulate crinoids, the indentations in the calyx at the base (just above the attachment for the stem), and where the basals and radials join (causing the radials to seem to bulge out), are unique to Iocrinus in the local fauna, giving the calyx a distinctive aspect compared to Dendrocrinus, Cupulocrinus, Isotomocrinus, Grenprisia, Daedalocrinus, Ottawacrinus, etc. The pronounced articulation facets on the arm segments is distinctive of Iocrinus, so even isolated arms can be distingushed from Dendrocrinus or Cupulocrinus, though the facets can be large (but smaller than in Iocrinus) in the latter genus. Lastly, one can just see a bit of the anal sack between the arms; the position indicates that the anal sack was relatively large, and one can perhaps just make out a hint of the typical Iocrinus ornamentation of strong horizontal ridges. Better prep of the anal sack would do a lot to confirm or refute the ID. One anomaly is that the stem appears to be round through it's length, whereas typically Iocrinus has a pentagonal stem that may become rounded just below the calyx. In this case it's possible that the stem is worn down and so the pentagonal structure is obscured, it's hard to tell from the photo. Both Iocrinus subcrassus and Iocrinus trentonensis occur in the Lindsey (=Cobourg) Formation in the area, but Iocrinus subcrassus has quite robust arms relative to the size of the calyx, as is also seen in the photographs, whereas Iocrinus trentonensis is more gracile, with slender Dendrocrinus-like arms. A somewhat relevant but non-morphological bit of information is that Iocrinus subcrassus is perhaps the most common crinoid found at the top of the Lindsey in the Ottawa area (about 100 miles NE of Prince Edward County), whereas Iocrinus trentonensis is a rare species found low in the Lindey (or perhaps in the Verulam, depending on where you draw the boundary), so one is just a lot more likely to encounter Iocrinus subcrassus. Overall, I have offered a tentative ID based on my familiarity with the relatively small crinoid fauna in the Ontario Ordovician, and the unique calyx morphology of Iocrinus within this fauna. I wouldn't try this without better photos if the specimen was from one of the Mississippian formations where hundreds of similar species may occur. Cheers, Don Edited July 17, 2012 by FossilDAWG Link to comment Share on other sites More sharing options...
pleecan Posted July 17, 2012 Author Share Posted July 17, 2012 Good response Don. Better photos are coming once I get a hold of of the fossil. I was there in the quarry when the crinoid was found in the quarry lying ontop of a weathered pile of material.... this specimen is not from a fresh blast. Link to comment Share on other sites More sharing options...
pleecan Posted July 17, 2012 Author Share Posted July 17, 2012 Kevin Brett concurs with Bill Hessin and Don that this fossil is Iocrinus. Link to comment Share on other sites More sharing options...
Herb Posted July 18, 2012 Share Posted July 18, 2012 Nice specimen! Picture doesn't look too bad to me. I think the Queen should have that mole looked at. "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...
Malcolmt Posted July 18, 2012 Share Posted July 18, 2012 Peter, your field photos are better than anything I can do!!!!!!!!!!! Link to comment Share on other sites More sharing options...
thanatocoenosis Posted July 18, 2012 Share Posted July 18, 2012 (edited) Lets be civilized about it. The photo is the best I could do given the moment.... I don't truck my equipment with me. You just got to wait. I did not use a tripod and the camera system is about $1000. The object is tiny and hard to photograph. I also resent the comment as being a poor example of photography! I don't need to show you guys anything with comments like that! So bear in mind I carry +30yrs of optics know how! PL I am sorry that you were offended by my response; I did not mean to impugn your skills as a photographer. Anyone that has been around this forum, for any length of time, is aware of the novel techniques that you employ to illuminate hard to image, and see, minutia of specimens. I was genuinely curious how someone could determine genera, much less specie, with a low resolution image. Determination of crinoids can be very tricky, and always the determining factor is counting plates, intricacies of the theca, and symmetry of the calyx. With the image supplied, I determined that it was probably an Inadunate... I was thinking Cladid, but if it is Iocrinus... well, you see. As I wrote above, I couldn't determine if infra-basals were present. That is a very important determining factor in the identification of any crinoid... some cladids are very similar to some disparids, the determinate is what plates are present. Once again, sorry for the miscommunication. EDIT: grammar Edited July 18, 2012 by thanatocoenosis 2012 NCAA Collegiate Round Ball Champs; and in '98, '96, '78, 58, '51, '49, and '48, too. Link to comment Share on other sites More sharing options...
thanatocoenosis Posted July 18, 2012 Share Posted July 18, 2012 In this case, I know the geology of the area, and spent several years becoming familiar with the local Ordovician echinoderm fauna. In this case, the arms lack pinnules, which excludes Glyptocrinus, Pycnocrinus, Archaeocrinus, Periglyptocrinus, and other less common taxa. Of course the cup shape and ornamentation is totally different in those genera too. Amongst the non-pinnulate crinoids, the indentations in the calyx at the base (just above the attachment for the stem), and where the basals and radials join (causing the radials to seem to bulge out), are unique to Iocrinus in the local fauna, giving the calyx a distinctive aspect compared to Dendrocrinus, Cupulocrinus, Isotomocrinus, Grenprisia, Daedalocrinus, Ottawacrinus, etc. The pronounced articulation facets on the arm segments is distinctive of Iocrinus, so even isolated arms can be distingushed from Dendrocrinus or Cupulocrinus, though the facets can be large (but smaller than in Iocrinus) in the latter genus. Lastly, one can just see a bit of the anal sack between the arms; the position indicates that the anal sack was relatively large, and one can perhaps just make out a hint of the typical Iocrinus ornamentation of strong horizontal ridges. Better prep of the anal sack would do a lot to confirm or refute the ID. One anomaly is that the stem appears to be round through it's length, whereas typically Iocrinus has a pentagonal stem that may become rounded just below the calyx. In this case it's possible that the stem is worn down and so the pentagonal structure is obscured, it's hard to tell from the photo. Both Iocrinus subcrassus and Iocrinus trentonensis occur in the Lindsey (=Cobourg) Formation in the area, but Iocrinus subcrassus has quite robust arms relative to the size of the calyx, as is also seen in the photographs, whereas Iocrinus trentonensis is more gracile, with slender Dendrocrinus-like arms. A somewhat relevant but non-morphological bit of information is that Iocrinus subcrassus is perhaps the most common crinoid found at the top of the Lindsey in the Ottawa area (about 100 miles NE of Prince Edward County), whereas Iocrinus trentonensis is a rare species found low in the Lindey (or perhaps in the Verulam, depending on where you draw the boundary), so one is just a lot more likely to encounter Iocrinus subcrassus. I just read your response. I tentatively accept your anecdotes, but is it monocylcic, or dicyclic? That is the determinate. I'm probably wrong as I thought it a cladid, but the devil is in the details. Are there infra-basals? See below a disparid and cladid from the Treatise. A dendocrinid... a dicyclic cladid An Iocrinid... a monoclyclic disparid 2012 NCAA Collegiate Round Ball Champs; and in '98, '96, '78, 58, '51, '49, and '48, too. Link to comment Share on other sites More sharing options...
FossilDAWG Posted July 18, 2012 Share Posted July 18, 2012 Hi thanatocoenosis, I appreciate your scepticism and rigor, it's good to get called on overconfidence once in a while. In this particular case, Iocrinus differs noticably from Dendrocrinus in having much more pronounced depressions that cause the radials to appear to bulge out of the calyx, and in the much more pronounced articulation facets in the arm primaries and secondaries. I certainly agree it would be useful to be able to clearly see the plate boundaries, and also the anal sac (which differs between the genera) for a very high confidence ID. Ultimately, though, photographs will always have limitations compared to having the specimen in hand (or under the microscope). I know of some dicyclic crinoids where the infrabasals are completely covered by the stem attachment, or are buried in a pocket formed from having the basals extended down to encompass the uppermost part of the stem. You could never see those infrabasals in a photograph, unless someone removed the calyx from the matrix and detached the stem. So, there will always be some level of uncertainty when one is working from photographs, unless they are the sort one would use to illustrate a published paper. I've been trying to ID some Mississippian crinoids I collected in New Mexico. Plate boundaries are very difficult to see on the actual specimens (these are batocrinids and cactocrinids), and you do indeed have to count interradials and such to distinguish between genera, such as Cactocrinus vs Nunnacrinus. In the papers where these genera were described, the illustrations consist of drawings that were prepared starting from photographs, but with the plate boundaries drawn on, as they are so subtle in most cases they can't be photographed. If you get the angle of the light just right on one part of the calyx, you still won't be able to see (or photograph) the plate boundaries just a cm to one side or the other. Cheers, Don Link to comment Share on other sites More sharing options...
thanatocoenosis Posted July 18, 2012 Share Posted July 18, 2012 (edited) Hi thanatocoenosis, I appreciate your scepticism and rigor, it's good to get called on overconfidence once in a while. In this particular case, Iocrinus differs noticably from Dendrocrinus in having much more pronounced depressions that cause the radials to appear to bulge out of the calyx, and in the much more pronounced articulation facets in the arm primaries and secondaries. Don Don, merocrinids are dicyclic; iocrinids are monocyclic. Once again, the devil is in the detail. The question is whether, or not, his specimen has infra basals. That is my argument. The differentiation of the cladids and disparids is dependent upon those distal plates... not what something looks like. The next thing you know, we will be visiting Indiana 9 and making a determination because... " it looks like it". Edited July 19, 2012 by thanatocoenosis 2012 NCAA Collegiate Round Ball Champs; and in '98, '96, '78, 58, '51, '49, and '48, too. Link to comment Share on other sites More sharing options...
pleecan Posted July 18, 2012 Author Share Posted July 18, 2012 Thanatocoenosis: Apology accepted. Don and Thanatocoenosis: Great discussion guys! I definitely will be posting better pictures when I get the specimen. : ) This forum is a great place to learn stuff! PL Link to comment Share on other sites More sharing options...
thanatocoenosis Posted July 19, 2012 Share Posted July 19, 2012 (edited) In this particular case, Iocrinus differs noticably from Dendrocrinus in having much more pronounced depressions Iocrinus differs from Dendocrinus in that Iocrinus is monocyclic and Dendocrinus is dicyclic(has infra basals); Both share other habits. EDIT: inclusion of material Edited July 19, 2012 by thanatocoenosis 2012 NCAA Collegiate Round Ball Champs; and in '98, '96, '78, 58, '51, '49, and '48, too. Link to comment Share on other sites More sharing options...
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