WiscoChick Posted April 26, 2022 Share Posted April 26, 2022 Need help confirming what I found. This speciman was found in Milwaukee, WI. I found it in some loose landscape rock around the building I work in. Unfortunately I don't have a ruler on me right now but it's about 2 inches long and 3/4 inches wide. Originally I thought it was agate but someone in my rock group on Facebook says it looks to be silicified stromatoporoid. After doing a Google search I came across stromatolites also. So I'm not sure which one it could be. It's a beautiful specimen. What looks to be quartz on the bottom and what I originally thought was agate surrounding it. Any ideas of what this could be? Thanks a ton! (Sorry about holding the speciman. These pics were taken when I found it and I have the specimen at home and not on me right now. I tried to crop out my fingers) Pics: side view, end view and top view Link to comment Share on other sites More sharing options...
DPS Ammonite Posted April 26, 2022 Share Posted April 26, 2022 (edited) You likely have a silicified stromatoporoids, sponges. Note the even layers and the pillers that go between the layers. Stromatolites have very erratic layers and have no pillers. https://en.m.wikipedia.org/wiki/Stromatoporoidea Edited April 26, 2022 by DPS Ammonite 1 1 My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted April 26, 2022 Share Posted April 26, 2022 Yes, the laminae, pillars and galleries all suggest a body fossil of a stromatoporoid. I think you can see mamelons on the bottom of the specimen in your second photograph, so maybe the fossil is upside down. Stromatolites are just sedimentary layers left by cyanobacteria and don't have an organized structure. 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
WiscoChick Posted April 26, 2022 Author Share Posted April 26, 2022 10 minutes ago, Tidgy's Dad said: Yes, the laminae, pillars and galleries all suggest a body fossil of a stromatoporoid. I think you can see mamelons on the bottom of the specimen in your second photograph, so maybe the fossil is upside down. Stromatolites are just sedimentary layers left by cyanobacteria and don't have an organized structure. What are mamelons? I'm sorry, I'm just a beginner learning about fossils. Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted April 26, 2022 Share Posted April 26, 2022 It's a very pretty specimen, by the way. Mamelons are lumpy bits on the top surface. 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
WiscoChick Posted April 26, 2022 Author Share Posted April 26, 2022 4 minutes ago, Tidgy's Dad said: It's a very pretty specimen, by the way. Mamelons are lumpy bits on the top surface. Oh ok, now I see it. Yes i would have to agree with you then. There are a bunch of bumps on the outside so it would in fact, be upside down. Thanks for the info! Yes, it is a pretty speciman. I have a few others I would like to post as well but I wanted to test out the waters of a forum. Never used one before. So far it's been way more helpful then my rock groups on Facebook! 1 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted April 26, 2022 Share Posted April 26, 2022 (edited) 12 minutes ago, WiscoChick said: Oh ok, now I see it. Yes i would have to agree with you then. There are a bunch of bumps on the outside so it would in fact, be upside down. Thanks for the info! Yes, it is a pretty speciman. I have a few others I would like to post as well but I wanted to test out the waters of a forum. Never used one before. So far it's been way more helpful then my rock groups on Facebook! We try our best, learn from each other, enjoy other people's specimens and have a lot of fun. A very warm welcome to TFF from Morocco. Edited April 26, 2022 by Tidgy's Dad 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
SilurianSalamander Posted January 13, 2023 Share Posted January 13, 2023 Stromatoporoid. Lovely find. I find a lot of pretty agatized stromatoporioids but none in these colors! Link to comment Share on other sites More sharing options...
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