Bronzviking Posted January 1, 2019 Share Posted January 1, 2019 Happy New Year everyone! I found this awesome little star-like fossil on a Tampa Bay beach in Florida. It's about an inch wide and has crystals in the center. It has a volcano look with grooves and appears to be a mold of something, but what? Thanks in advance. Link to comment Share on other sites More sharing options...
ynot Posted January 1, 2019 Share Posted January 1, 2019 Barnacle(?) 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...
MrR Posted January 1, 2019 Share Posted January 1, 2019 This newbie's WAG would be barnacle. But take what I hazard with a large grain. Cheers. (And it's ynot by a nose.) Link to comment Share on other sites More sharing options...
Bronzviking Posted January 1, 2019 Author Share Posted January 1, 2019 4 minutes ago, ynot said: Barnacle(?) A one inch barnacle without a hole? Link to comment Share on other sites More sharing options...
Rockwood Posted January 1, 2019 Share Posted January 1, 2019 Mold of scelractinian coralite. 7 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted January 1, 2019 Share Posted January 1, 2019 3 minutes ago, Rockwood said: Mold of scelractinian coralite. Yup. +1 Scleractinian coral mold of calice. 2 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
ynot Posted January 1, 2019 Share Posted January 1, 2019 15 minutes ago, Bronzviking said: A one inch barnacle without a hole? I was thinking steinkern, but now think the others are correct with coral. 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...
Bronzviking Posted January 1, 2019 Author Share Posted January 1, 2019 9 minutes ago, Tidgy's Dad said: Yup. +1 Scleractinian coral mold of calice. The fossil is not concave, it is convex. Also is scleractinia the right time period? Thanks Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted January 1, 2019 Share Posted January 1, 2019 2 minutes ago, Bronzviking said: The fossil is not concave, it is convex. Also is scleractinia the right time period? Thanks Yes, it is convex because it is the result of infilling of the original concave coral opening. Florida is more likely to have scleractinians than other major extinct Palaeozoic groups and also this looks like one, not a usual pattern for a rugose coral, for example. 7 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
digit Posted January 1, 2019 Share Posted January 1, 2019 1 hour ago, Bronzviking said: It has a volcano look with grooves and appears to be a mold of something, but what? I love the evocative imagery here. Indeed, as others have stated--this is a steinkern (negative mold) from a larger coral polyp. Pressing it into some Play-Doh (or modeling clay) might leave a decent positive image which would be more easy to see and understand. You can see the negatives of the septa (your "grooves") as well as a circle of dimples around the center corresponding to pointed structures in the columella (the base where the coral supports itself). Here's a reasonable web link I found showing the structure of the coral polyp skeleton: https://coral.aims.gov.au/info/structure-skeleton.jsp The species of modern colonial corals with the biggest polyps still living in Florida waters would probably be Montastraea cavernosa but its corallites are in the range of 1/4" (6-7 mm). At around 1" (~25mm) in diameter this would have to have been from one of the larger solitary coral polyps. Solitary corals are part of the modern coral landscape but usually tend to be either deep or hidden in recesses and most divers/snorkelers fail to notice them. I couldn't hazard a guess as to the ID but it is possible someone on this forum or folks like Roger Portell (Invertebrate Collection Director) of the Florida Museum of Natural History (FLMNH) might have a learned opinion if you want a more detailed ID. Cheers. -Ken 5 Link to comment Share on other sites More sharing options...
Bronzviking Posted January 2, 2019 Author Share Posted January 2, 2019 That seems like a very strong possibility, thank you for explaining that in detail. I was thinking it resembled a striped false limpet. Since they are shaped like oval-base volcanoes, but with no top hole. Color is cream with numerous brown radial stripes. What do you guys think about a mold of this shell? Link to comment Share on other sites More sharing options...
Bronzviking Posted January 2, 2019 Author Share Posted January 2, 2019 2 hours ago, Tidgy's Dad said: Yes, it is convex because it is the result of infilling of the original concave coral opening. Florida is more likely to have scleractinians than other major extinct Palaeozoic groups and also this looks like one, not a usual pattern for a rugose coral, for example. So your saying it's like a reverse mold of the cup. Is this unusual or a rare fossil? Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted January 2, 2019 Share Posted January 2, 2019 13 minutes ago, Bronzviking said: So your saying it's like a reverse mold of the cup. Is this unusual or a rare fossil? Fairly common, but very pretty! 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
digit Posted January 2, 2019 Share Posted January 2, 2019 1 hour ago, Bronzviking said: Color is cream with numerous brown radial stripes. What do you guys think about a mold of this shell? Nope. The inside of limpet shells are in fact rather smooth. Your fossil negative mold is the wrong convexity for the outside of a limpet. I've seen a lot of coral skeletons on beaches and fossil coral reefs in the Keys and this is definitely a negative of a larger coral polyp. If you can find some modeling clay, silly putty, or something like silicone rubber to make a positive image from this negative, you'll see how it looks like a coral skeleton. Post photos if you do manage to make the positive image. Would be interesting to see. Cheers. -Ken 2 Link to comment Share on other sites More sharing options...
Herb Posted January 2, 2019 Share Posted January 2, 2019 piece of coral "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...
KimTexan Posted January 2, 2019 Share Posted January 2, 2019 It’s definitely coral. It is fairly comon. I don’t know about for Florida, but I’d think it would have to be considering all the other marine fossils and corals that show up. 1 Link to comment Share on other sites More sharing options...
fifbrindacier Posted January 2, 2019 Share Posted January 2, 2019 5 hours ago, Rockwood said: Mold of scelractinian coralite. Absolutely, a nice scleractinian coral, i have some from the eiffelian that looks like yours (not saying yours is from the same species) Calceola sandalina : Cyathophyllum : 1 "On ne voit bien que par le coeur, l'essentiel est invisible pour les yeux." (Antoine de Saint-Exupéry) "We only well see with the heart, the essential is invisible for the eyes." In memory of Doren Link to comment Share on other sites More sharing options...
Rockwood Posted January 2, 2019 Share Posted January 2, 2019 7 hours ago, digit said: Nope. The inside of limpet shells are in fact rather smooth. Your fossil negative mold is the wrong convexity for the outside of a limpet. I've seen a lot of coral skeletons on beaches and fossil coral reefs in the Keys and this is definitely a negative of a larger coral polyp. If you can find some modeling clay, silly putty, or something like silicone rubber to make a positive image from this negative, you'll see how it looks like a coral skeleton. Post photos if you do manage to make the positive image. Would be interesting to see. Cheers. -Ken It seems like this process could occur naturally to a limpet shell, but it would have to be rare. Link to comment Share on other sites More sharing options...
Bronzviking Posted February 5, 2019 Author Share Posted February 5, 2019 I came across a picture of a antillophyllia chipolana in my Florida's Fossil book by Robin C. Brown. My mold resembles this picture and it reminds me of a horn coral. I found an example in Harry Pristis library posted below. What do you think? Link to comment Share on other sites More sharing options...
Rockwood Posted February 5, 2019 Share Posted February 5, 2019 12 minutes ago, Bronzviking said: it reminds me of a horn coral. They do sometimes get referred to as horn coral, but rugose horn coral became extinct at end Permian. 1 Link to comment Share on other sites More sharing options...
digit Posted February 5, 2019 Share Posted February 5, 2019 Indeed. rugose (horn) corals died out at the close of the Permian (did not squeeze through the Permian-Triassic extinction event). Most modern day scleractinian (hard reef-building) corals tend to be colonial but there are still a number of solitary polyp corals--commonly called "cup corals" around today. Most tend to be deep water species on mud flats well below the level where light can penetrate. They tend to be slow growing and without the symbiotic algae (zooxanthellae) they are not able to precipitate calcium carbonate fast enough to be a significant contributor to reef development. Many of the shallow water cup corals tend to grow in cave recesses or under overhangs in the dimly lit area usually carpeted with sponges and bryozoans. Cheers. -Ken 2 Link to comment Share on other sites More sharing options...
Bronzviking Posted February 5, 2019 Author Share Posted February 5, 2019 Yes I know horn coral is extinct and not found in Florida. I guess you guys misunderstood me. I was asking if my fossil could be a antillophyllia chipolana mold, vs a mold of scelractinian coralite? Thanks! @Rockwood @digit Link to comment Share on other sites More sharing options...
Rockwood Posted February 5, 2019 Share Posted February 5, 2019 Matching a mold to a body fossil of scelractinian coral is far far over my head. Sorry. Link to comment Share on other sites More sharing options...
abyssunder Posted February 5, 2019 Share Posted February 5, 2019 Your specimen looks like the infill sediment of a solitary scleractinian coral calice like Antillophyllia chipolana. If you make a mold of it you can compare to A. chipolana to see if the septal morphology fits. 1 " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Bronzviking Posted February 5, 2019 Author Share Posted February 5, 2019 13 minutes ago, abyssunder said: Your specimen looks like the infill sediment of a solitary scleractinian coral calice like Antillophyllia chipolana. If you make a mold of it you can compare to A. chipolana to see if the septal morphology fits. So what your saying is Antillophyllia chipolana is one of many types of scleractinian corals? I made a mold and it does look very similar, but I guess it's like comparing apples to oranges at this point, right? Thank you for your feedback! Link to comment Share on other sites More sharing options...
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