elcheecho Posted September 21, 2014 Share Posted September 21, 2014 Hello, I recently came upon this fossil at a garage sale that appeared to be a rather large Orthoceras. The man selling it claimed it was a 12 myo fossil of something called a Cyclopger. I did a little research on my own and didn't find any information on any cephalopod species by the name of "cyclopger." Or for that matter, any information on any Orthoceras species that lived 12 million years ago. So, it seems that the man selling it didn't know what he was really talking about, which of course makes me wonder: Just what is this thing? From what I know, it was found in limestone in Golden Valley, MN, and the fossilized shell appears to be about 16" long. If anyone out there knows what this might be, my sense of curiosity would greatly appreciate it. Link to comment Share on other sites More sharing options...
Auspex Posted September 21, 2014 Share Posted September 21, 2014 Well, it is a straight-shelled cephalopod, but the gentleman had the age wrong (and the name he used id indecipherable). Compare it to Dawsonoceras. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
FossilDAWG Posted September 21, 2014 Share Posted September 21, 2014 At one time the name "Cycloceras" was used as a catch-all for strongly ribbed orthoconic nautiloids. "Cyclopger" may have been some collector's slang for such fossils. Your specimen is definitely an orthoconic nautiloid, obviously much much older than 12 million years; such fossils can be found in Ordovician, Silurian, and Devonian rocks. Dawsonoceras is a good suggestion if the specimen is Silurian, but other genera apply to Ordovician and Devonian forms. Don Link to comment Share on other sites More sharing options...
Herb Posted September 21, 2014 Share Posted September 21, 2014 Very nice specimen. Looks like a Silurian "Dawsonoceras" "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...
elcheecho Posted September 22, 2014 Author Share Posted September 22, 2014 Excellent information, Dawsonoceras looks like a pretty good fit from what I've seen. Thank you all for the quick and interesting replies. Link to comment Share on other sites More sharing options...
fossilized6s Posted September 22, 2014 Share Posted September 22, 2014 I agree with Dawsonoceras and Silurian. I've found many of them in limestone around Lake Mich. ~Charlie~ "There are those that look at things the way they are, and ask why.....i dream of things that never were, and ask why not?" ~RFK ->Get your Mosasaur print ->How to spot a fake Trilobite ->How to identify a CONCRETION from a DINOSAUR EGG Link to comment Share on other sites More sharing options...
piranha Posted September 22, 2014 Share Posted September 22, 2014 Since Dawsonoceras is restricted to the Silurian in North America, it should be noted, this specimen found in Golden Valley is certainly not Silurian. Hennepin County is Cambrian and Ordovician and according to the attached USGS geo map, Golden Valley is entirely Ordovician. An important caveat: a Google search for 'Silurian Minnesota' will yield many results of the old literature before the Ordovician was officially defined. Quote There is no Silurian in Minnesota today, but there was until the early Devonian when there was a particularly low sea level (for the Paleozoic) and it was eroded away. Today there is a buried cliff of Silurian rocks just 30 rniles south of Minnesota, a few miles south of Decorah, lowa. These are limestones with little clay content, so it is very likely that large parts of southern Minnesota were originally covered with Silurian rocks. Sloan, R.E. (2005) Minnesota Fossils And Fossiliferous Rocks. Link to comment Share on other sites More sharing options...
fossilized6s Posted September 22, 2014 Share Posted September 22, 2014 (edited) So if this isn't Dawsonoceras would this be the internal chamber of a Ordovician Ceph (that were more smooth and round)? Edited September 22, 2014 by fossilized6s ~Charlie~ "There are those that look at things the way they are, and ask why.....i dream of things that never were, and ask why not?" ~RFK ->Get your Mosasaur print ->How to spot a fake Trilobite ->How to identify a CONCRETION from a DINOSAUR EGG Link to comment Share on other sites More sharing options...
Auspex Posted September 22, 2014 Share Posted September 22, 2014 We do not really know where it was found (given the inaccuracy of the other information that accompanied it from the seller). Without some more solid provenance, about all we can conclude with confidence is that it is from the Paleozoic, and is far older than 12 million years. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
fossilized6s Posted September 22, 2014 Share Posted September 22, 2014 Haha, you know Chas i was thinking the same thing considering the seller was off 450 million years give or take. ~Charlie~ "There are those that look at things the way they are, and ask why.....i dream of things that never were, and ask why not?" ~RFK ->Get your Mosasaur print ->How to spot a fake Trilobite ->How to identify a CONCRETION from a DINOSAUR EGG Link to comment Share on other sites More sharing options...
piranha Posted September 22, 2014 Share Posted September 22, 2014 The name and age given by the seller are obviously erroneous, but if he was the finder, let's hope the locality information is accurate. At a minimum, a Minnesota find excludes the Silurian and Dawsonoceras. The only important provenance is verifying that it was collected in Minnesota. Link to comment Share on other sites More sharing options...
Missourian Posted September 22, 2014 Share Posted September 22, 2014 Sometimes there are issues with labels on fossils, even from 'reputable' sources. One example that comes to mind is concretions from the Pennsylvanian Knob Noster site in Missouri. The specimens are labeled as coming from the 'Braidwood Formation'. A problem is that there is no such formation. Actually, the specific formation of the deposit has yet to be determined (I label my specimens as 'Upper Cherokee Group'). I figure the seller(s) labeled the concretions as such because they are similar in age and nature with the Braidwood-fauna specimens of Mazon Creek. Even so, the formation there is the Carbondale, which is not valid in Missouri anyway. Ok, my problem with all of this -- and with the orthocone shown above -- is that people just pull information out of a hat (or from thin air) when they label a specimen. It'd be better to just say 'Ordovician', 'Paleozoic', or even 'I don't know', than to unnecessarily confuse matters. The real problem is unknowingly having an accurate-looking label that is really just a figment of someone's imagination. It's even worse than having a fossil with no labeling whatsoever. Imagine a museum inheriting an otherwise scientifically valuable collection that is riddled with such mislabelings. Context is critical. Link to comment Share on other sites More sharing options...
howard_l Posted September 22, 2014 Share Posted September 22, 2014 (edited) Dawsonoceras is most common in the Silurian but the Family Dawsonoceratidae ranges from the Ordovician into the Devonian. I have seen some European papers that indicate Dawsonoceras as being from both Ordovician and Silurian. The matrix sure looks Silurian but saying that from a picture is way out there, Edited September 22, 2014 by howard_l Howard_L http://triloman.wix.com/kentucky-fossils Link to comment Share on other sites More sharing options...
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