JUAN EMMANUEL Posted May 23, 2019 Share Posted May 23, 2019 Hi guys so I have this Hebertella occidentalis specimen I collected yesterday from the Credit River at Streetsville, Mississauga, Ontario, which belongs to the Upper Member of the Georgian Bay Formation. Do these look like predation marks? There are also what appears to some crystallized grains inside these marks and I think they could be some sort of calcite. Sorry for the noisy grain of the image, but I hope this will help. Link to comment Share on other sites More sharing options...
ynot Posted May 23, 2019 Share Posted May 23, 2019 I do not see predation here. Looks like natural breakage showing geodized interior. Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
Mediospirifer Posted May 23, 2019 Share Posted May 23, 2019 I see a few spots on that shell that could be worm borings: It's hard to tell from the photo whether 1 and 2 are boreholes or blobs of matrix stuck to the shell. The marks at 3 look like borings, but they look like marks I've seen that I attribute to burrowing in a dead shell. If 1 and 2 are holes, they could also be from postmortem burrowing rather than predation. I have a few Ordovician bored brachiopods that I wanted to know more about. Apparantly, the modern gastropod families that are known to prey on other mollusks by boring shells don't appear in the fossil record until well after the Ordovician (although I don't remember offhand what era they do appear in). There are certainly examples of hardground burrowings from that era that pierce multiple shells. The edge damage in your red circle looks like natural breakage. Interesting specimen! 2 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted May 23, 2019 Share Posted May 23, 2019 I think it's marks left by epibionts that were fused to the shell and either broke off or slightly bored into it. The edge piece, weakened by the borings has broken off. Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
doushantuo Posted May 23, 2019 Share Posted May 23, 2019 Agree with Medio &Tidgy there BTW: brachpredatbullmarsci29320653_s12.pdf Michal Kowalewski* and Karl W. Flessa BULLETIN OF MARINE SCIENCE, 66(2): 405–416, 2000 *author of some high-end(quantitative) brachiopod taphonomy literature a documented case/paywalled: Cephalopod Predation on a Desmoinesian Brachiopod from the Naco Formation, Central Arizona David K. Elliott and Douglas C. Brew Journal of Paleontology Vol. 62, No. 1 (Jan., 1988), pp. 145-147 Link to comment Share on other sites More sharing options...
Herb Posted May 23, 2019 Share Posted May 23, 2019 looks like some borings, maybe worms or sponges "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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