keldeo072 Posted September 24, 2018 Share Posted September 24, 2018 Hey guys I need some help identifying these possible trilobites. Any information about which part of the trilobite the specimen is, species, etc would be appreciated. All of these specimens were found in Cincinnati, ohio in rocks from the Ordovician period. These 3 similar looking fossils are about 1 centimeter in length. This fossil is 3 centimeters in length. Showing front and back. This trilobite impression is 6 centimeters in length and 4.5 centimeters in width. Link to comment Share on other sites More sharing options...
piranha Posted September 24, 2018 Share Posted September 24, 2018 14 minutes ago, keldeo072 said: Flexicalymene Flexicalymene Flexicalymene Isotelus Isotelus 4 Link to comment Share on other sites More sharing options...
erose Posted September 24, 2018 Share Posted September 24, 2018 IMHO that last one is most definitely NOT Isotelus. Piranha, why that ID? We need better stratigraphy to SWAG that one. It may be one of the less common Cinci bugs. The others are a good guess, but there isn't much to go on. 1 Link to comment Share on other sites More sharing options...
Herb Posted September 25, 2018 Share Posted September 25, 2018 I do not think the last one is Isotelus either. 1 "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...
piranha Posted September 25, 2018 Share Posted September 25, 2018 The exoskeleton is not preserved. It is the internal mold of a juvenile Isotelus. Isotelus figure from: Ludvigsen, R. 1979 The Ordovician trilobite Pseudogygites Kobayashi in eastern and Arctic North America. Royal Ontario Museum, Life Sciences Contributions, 120:1-41 LINK 2 Link to comment Share on other sites More sharing options...
Peat Burns Posted September 25, 2018 Share Posted September 25, 2018 What's throwing me off as far as Isotelus goes is the apparent "ridge" down the center. 1 Link to comment Share on other sites More sharing options...
Herb Posted September 25, 2018 Share Posted September 25, 2018 If you want to say it is a Pseudogygites kobayash , I think I would agree with that. "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...
piranha Posted September 25, 2018 Share Posted September 25, 2018 27 minutes ago, Peat Burns said: What's throwing me off as far as Isotelus goes is the apparent "ridge" down the center. The "ridge" is not a morphologic feature. Look again closely, the "ridge" travels through the cephalon to the pygidium. The ridge is an artifact of lateral compression. 25 minutes ago, Herb said: If you want to say it is a Pseudogygites kobayash , I think I would agree with that. There is no species named: "Pseudogygites kobayashi". Pseudogygites Kobayashi from the Ludvigsen title is a reference to Kobayashi who established the genus. The OP stated the trilobites are from Cincinnati. Pseudogygites is not found in Ohio. Isotelus is used in that paper to compare the growth stages vs Pseudogygites. 5 Link to comment Share on other sites More sharing options...
erose Posted September 26, 2018 Share Posted September 26, 2018 22 hours ago, piranha said: The exoskeleton is not preserved. It is the internal mold of a juvenile Isotelus. Isotelus figure from: Ludvigsen, R. 1979 The Ordovician trilobite Pseudogygites Kobayashi in eastern and Arctic North America. Royal Ontario Museum, Life Sciences Contributions, 120:1-41 LINK Very well done. The eyes certainly looked like Isotelus but I had never seen a juvenile preserved like that. I stand corrected. Link to comment Share on other sites More sharing options...
Herb Posted September 26, 2018 Share Posted September 26, 2018 21 hours ago, piranha said: The "ridge" is not a morphologic feature. Look again closely, the "ridge" travels through the cephalon to the pygidium. The ridge is an artifact of lateral compression. There is no species named: "Pseudogygites kobayashi". Pseudogygites Kobayashi from the Ludvigsen title is a reference to Kobayashi who established the genus. The OP stated the trilobites are from Cincinnati. Pseudogygites is not found in Ohio. Isotelus is used in that paper to compare the growth stages vs Pseudogygites. You are correct, piranha "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...
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