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BananaNemesis

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We found this a few years ago at a beach in PBC Florida... I think there had been a renourishment and they had brought sand up from off shore. We don’t know what it is.. do you?

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Amazing!! I have never seen anything like it.  You already have me thinking "ivory" or tusk and I love those.  Can not help here...just watch and see if someone IDs it. :popcorn:

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The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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Gorgonian holdfast, or in other words it is the part of a sea fan or sea whip that attaches to the sea floor.

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33 minutes ago, Al Dente said:

Gorgonian holdfast, or in other words it is the part of a sea fan or sea whip that attaches to the sea floor.

Great ID... Found this link and photo

http://woostergeologists.scotblogs.wooster.edu/tag/italy/

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Learn something new...

The White Queen  ".... in her youth she could believe "six impossible things before breakfast"

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+1 for gorgonian holdfast. The brown woody/horny material definitely looks like gorgonin which forms the flexible internal skeleton of gorgonian soft corals (sea fans and sea whips). These corals are members of the subclass Octocorallia (meaning that their polyps have 8 tentacles rather than multiples of 6 as do the Hexacorallia which includes the hermatypic reef building corals). The thing that made me take pause was the base which is calcium carbonate. Though this base looks like it came from the same animal I believe it is actually part of the limestone structure of the reef created by other reef building corals and/or coralline algae.

 

I usually see life gorgonians on the reef and we often pay attention to gorgonians bases and what they may be overgrowing on the reef while doing point-counts along benthic transects during surveys. I rarely get to see the points of attachment below the tissue of the live animal and mostly get to see the gorgonin skeletons when they are washed up on beaches or laying in sand channels after major storms have moved through an area. Unlike the reef building corals, these "soft" corals are not able to put down a calcium carbonate substrate and so the limestone part of your sample was not originally part of the gorgonian but it certainly seems to have been shaped by it. The smooth polished upper surface with the fine striations in it seem to indicate that the tissue at the base of the gorgonian may have chemically eroded and smooth the surface as it overgrew it.

 

So you can get some idea what this might have looked like when alive, here are a few gorgonian bases from my coral reef survey teaching materials.

 

Cheers.

 

-Ken

 

Gorgonian1.jpg    Gorgonian2.jpg    Gorgonian3.jpg

 

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Another vote for gorgonian holdfast. I remember this in another thread a while back.

“...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin

Happy hunting,

Mason

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35 minutes ago, digit said:

Though this base looks like it came from the same animal I believe it is actually part of the limestone structure of the reef created by other reef building corals and/or coralline algae.

Ken - My understanding is that some species have calcified bases but the rest of the animal lacks carbonate structure. We find the bases frequently in the Eocene limestones of North Carolina and they usually have the concentric growth rings.

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Nice! I like to learn new things and flesh out the corners of my understanding. As I mentioned, I usually see these when they are alive and my experience with dead (or fossilized) gorgonians is near nil.

 

I also know my Tropical Western Atlantic fish species very well but I can have a hard time identifying a parrotfish, snapper, grunt or grouper in a fish market because all of the coloration clues that I'm used to in a live fish have usually disappeared and are replaced with new "fish market" coloration patterns.

 

Cheers.

 

-Ken

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I love this. :wub:

Never seen a fossil gorgonian before, live ones yes, fossils, no. 

This forum is really increasing my understanding of this amazing planet. 

Thanks for posting BananaNemesis! 

Great find and welcome to the forum! 

Life's Good!

Tortoise Friend.

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It's a very nice find. :) Congrats!

No doubt, the specimen in question is an octocoral holdfast.

Compared to the one from J. S. Jell et al. 2011. Australian Cretaceous Cnidaria and Porifera. Alcheringa, 35: 241-284 , clearly has a good resemblance, although the are from different geological time and location.

 

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(Every time when I see something that confusingly looks like an antler, it reminds me of a gorgonian. :))

" 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. "

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