Mainefossils Posted June 19, 2021 Share Posted June 19, 2021 When I first started prepping this one, only the tip of the bottom right corner was showing. I initially that that it was a trilobite free cheek, which is quite a common find for this formation. About half-way through, I realized that it was not what I had initially thought. Now that I see it fully prepped, I have absolutely no idea what it is. Approximately half of it had crumbled before I started preparing it, due to the soft siltstone it was preserved in. Any help would be greatly appreciated. The pictures are taken with direct light, as there are no small details on the surface that will be shown with raking light. The scale shown is in millimeters. It is from the Leighton Formation; which is Silurian, Pridoli. Here are the photos: 1 The more I learn, the more I find that I know nothing. Regards, Asher Link to comment Share on other sites More sharing options...
Plantguy Posted June 20, 2021 Share Posted June 20, 2021 Interesting tidbit. I couldnt decide initially if it was a bivalve fragment but it strikes me now that maybe its actually part of a trilobite thorax...pleural lobe/furrows? Here's a picture to show the area of a trilobite that I'm referring to circled in red...just happens to actually be one from the Leighton formation....Not suggesting its that genus/species-I defer to the invert folks and Maine experts which we have to sort thru what it actually is...just my 2 cents from someone who hasnt done any Silurian hunting in a good long time... Very good photos!!. Hope someone can tell for sure what you have and eliminate my speculation. Source: https://digitalmaine.com/cgi/viewcontent.cgi?article=1575&context=mgs_publications Virtual Tour of Maine's Fossils Maine Geological Survey, Department of Agriculture, Conservation & Forestry Regards, Chris 3 Link to comment Share on other sites More sharing options...
Mainefossils Posted June 20, 2021 Author Share Posted June 20, 2021 @Plantguy Thanks so much for your help! I did not realize that some trilobites had branching pleural lobes like that. It really makes sense now, as I have just finished prepping out a more complete thoracic segment that matches what you have shown. I will post pictures of it soon. Thanks! The more I learn, the more I find that I know nothing. Regards, Asher Link to comment Share on other sites More sharing options...
Mainefossils Posted July 4, 2021 Author Share Posted July 4, 2021 I am sorry it took me so long to take a picture of this specimen, @Plantguy. Better late then never, I suppose. The specimen below is an external mold, preserved in a gray shale, with pockets of siltstone around it. Thanks for your patience! 1 The more I learn, the more I find that I know nothing. Regards, Asher Link to comment Share on other sites More sharing options...
Plantguy Posted July 4, 2021 Share Posted July 4, 2021 1 hour ago, Mainefossils said: I am sorry it took me so long to take a picture of this specimen, @Plantguy. Better late then never, I suppose. The specimen below is an external mold, preserved in a gray shale, with pockets of siltstone around it. Thanks for your patience! No problem. I'm gonna ask for help from others for their insights as I'm out of my league...hoping Scott and/or others can chime in... @piranha Scott, Can u verify if either of the frags are really bug related?? Anything further? Regards, Chris 1 Link to comment Share on other sites More sharing options...
EMP Posted July 5, 2021 Share Posted July 5, 2021 On 6/19/2021 at 11:58 AM, Mainefossils said: When I first started prepping this one, only the tip of the bottom right corner was showing. I initially that that it was a trilobite free cheek, which is quite a common find for this formation. About half-way through, I realized that it was not what I had initially thought. Now that I see it fully prepped, I have absolutely no idea what it is. Approximately half of it had crumbled before I started preparing it, due to the soft siltstone it was preserved in. Any help would be greatly appreciated. The pictures are taken with direct light, as there are no small details on the surface that will be shown with raking light. The scale shown is in millimeters. It is from the Leighton Formation; which is Silurian, Pridoli. Here are the photos: 10 hours ago, Mainefossils said: I am sorry it took me so long to take a picture of this specimen, @Plantguy. Better late then never, I suppose. The specimen below is an external mold, preserved in a gray shale, with pockets of siltstone around it. Thanks for your patience! The first one looks like some segments from a trilobite thorax to me, based on the possible furrows. The second one looks like a brachiopod fragment at the top and another partial trilobite thoracic segment below it. Probably a molt fragment. A good rule of thumb is that trilobite thoracic segments will have furrows or little "depressions" in them whereas brachiopods will typically display things like growth rings and bifurcation with their ribs. Link to comment Share on other sites More sharing options...
Mainefossils Posted July 5, 2021 Author Share Posted July 5, 2021 (edited) 11 hours ago, EMP said: The first one looks like some segments from a trilobite thorax to me, based on the possible furrows. The second one looks like a brachiopod fragment at the top and another partial trilobite thoracic segment below it. Probably a molt fragment. A good rule of thumb is that trilobite thoracic segments will have furrows or little "depressions" in them whereas brachiopods will typically display things like growth rings and bifurcation with their ribs. Thanks for your option! I am sorry that I was vague in my description, but I was describing the mold fragment, not the brachiopod above. As it is an external mold, it is rather hard to see its depth, but I will try to make a cast of it soon. The brachiopod above is a partial Camarotoechia leightoni. Thanks! Edited July 5, 2021 by Mainefossils The more I learn, the more I find that I know nothing. Regards, Asher Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now