Bev Posted July 18, 2013 Share Posted July 18, 2013 Ordovician. Galena Formation. SE MN I am having a devil of a time trying to figure out cephalopods from gastropods. When I see pieces like this, I throw them on the junk pile and write them off to broken gastropods. Actually, I've been throwing them into five gallon pails with other junk fossils to give away for kids sandbox fossil hunts. It sorta kinda reminds me of a Maclurite, but not. And I've seen them much looser than this one. Gastro = stomach pod = foot Stomach in foot Ceph = brain pod = foot Brain in foot I think I'm learning this right... OR it could be an infill of a gastropod? Or an infill of a ceph? I'm thinking this example would be an infill of a gastropod... And then, do YOU see these as "junk" fossils? So, I REALLY APPRECIATE YOUR PATIENCE! Thanks for looking. Take a stab at it... I can't be the only one in this boat. Bev The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
Herb Posted July 18, 2013 Share Posted July 18, 2013 (edited) Too old for a Maclurite, I think you are probably right with a gastropod. Mostly, in the Ordovician and Devonian, if it looks like a snail it probably is a snail, and most will be internal casts. Most, but not all, common O and D cephalopods tend to be straight shelled and segmented, some with slight curves at the end. If it is segmented it is most likely a ceph. Interesting looking piece. Edited July 18, 2013 by Herb "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...
Fossildude19 Posted July 18, 2013 Share Posted July 18, 2013 It's not too old for Maclurites, (The Macluritidae ranged from Lower Ordovician to Devonian) but I don't think it looks quite right for Maclurites, although it could be an internal cast. Gastropod is my vote, anyway. Regards, Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 IPFOTM -- MAY - 2024 _________________________________________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
Herb Posted July 18, 2013 Share Posted July 18, 2013 It's not too old for Maclurites, (The Macluritidae ranged from Lower Ordovician to Devonian) but I don't think it looks quite right for Maclurites, although it could be an internal cast. Gastropod is my vote, anyway. Regards, You are correct, my bad. I was thinking of a Cretaceous specimen that looks similar. We do not have (Maclurites) in the Ord. in my area. Or at least I have never found one or seen one found by anyone. "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...
Caleb Posted July 18, 2013 Share Posted July 18, 2013 It is a Maclurites gastropod. Coiled nautaloid cephalopods are quite uncommon in SE Minnesota, but they do exist and will be segmented. Caleb Midwestpaleo.com Link to comment Share on other sites More sharing options...
Bev Posted July 18, 2013 Author Share Posted July 18, 2013 Thanks Caleb, an infill? FYI guys, I find Maclurites all the time! They are like the Fillmore County Fossil. Everyone has at least one in their rock gardens and usually a few cephalopods too. I have like a 5 gallon bucket of them. And my avatar is a Mac. So, do you guys see these broken pieces as having any value? Bev The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
Caleb Posted July 18, 2013 Share Posted July 18, 2013 All of the Maclurites I have collected out of the Galena Formation have been internal molds. The shell material is rarely preserved but I have heard of some cases. I believe this species is Maclurites crassus. It's not too old for Maclurites, (The Macluritidae ranged from Lower Ordovician to Devonian) but I don't think it looks quite right for Maclurites, although it could be an internal cast. Gastropod is my vote, anyway. Regards, I think the reason it looks different is that it's completely free of matrix. Here are a couple specimens of Maclurites crassus I had at MAPS. 1 Caleb Midwestpaleo.com Link to comment Share on other sites More sharing options...
Bev Posted July 18, 2013 Author Share Posted July 18, 2013 Wow, I wasn't even aware that there were different types of Macs! The more I learn the less I know.... The more I learn, I realize the less I know. BluffCountryFossils.NET Fossil Adventure Blog Go to my Gallery for images of Fossil Jewelry, Sculpture & Crafts Pinned Posts: Beginner's Guide to Fossil Hunting * Geologic Formation Maps Link to comment Share on other sites More sharing options...
Indy Posted July 18, 2013 Share Posted July 18, 2013 There are often a number of different species of most fossils. Flash from the Past (Show Us Your Fossils)MAPS Fossil Show Link to comment Share on other sites More sharing options...
AgrilusHunter Posted July 18, 2013 Share Posted July 18, 2013 The more I learn the less I know.... Same here Bev! (Hence my signature line ) That is one cool looking snail by the way and I think saving your discards for sandbox fossils is a great idea. We do the same thing here with discard ferns and cyperites. I might steal your sand box idea too, that sounds like a lot of fun. "They ... savoured the strange warm glow of being much more ignorant than ordinary people, who were only ignorant of ordinary things." -- Terry Pratchett Link to comment Share on other sites More sharing options...
BobWill Posted July 18, 2013 Share Posted July 18, 2013 Your capacity for learning is greatly enhanced by your willingness to ask these questions. When you do it also teaches us all something, so keep 'em coming I think the interpretation used for the term cephalopod is "head" rather than "brain". Maybe that makes a little more sense. Also when we use the term "infill" it's usually for a burrow hole. The fossils of snails ( and other shelled creatures) without the shells are called internal molds in paleo textbooks however some call them internal casts. Link to comment Share on other sites More sharing options...
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