Ordovician Sponge

Terri

Sepia elegans
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#1
This ?gastropod is from the Bigby-Cannon Limestone in Smith Co. Tn. I've never found one like this and the closest I've found in my browsings is possibly in the Strombidae family? Not the best pictures but maybe there's enough there to point me in the right direction. It's about 3cm. across and a couple high. Any ideas?
 

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DWhatley

Cthulhu
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#2
On all your other posts I can find at least some of what I should be looking for and Kevin's added pencil marks bring out the rest but I have no clue where I am supposed to be looking in this one. WHERE is it?
 

Terri

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#3
It's the blob in the center, top of pic.:heee:. the pic. will enlarge a couple of times, then you should be able to see kindof a semi-circle with little conical shaped thingies and then just above that another row of slightly smaller ones, I can see it kind of continuing in that pattern if the top of the fossil hadn't been broken (probably by the guys that mow up there a couple times a year). I've been looking at these pictures for months and haven't been able to get back there for better pics. Kevin is so good at seeing what isn't there, I thought he might be able to figure it out.:roll:
 

Terri

Sepia elegans
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#7
Thanks Kevin, I don't think I would ever have thought to search sponges on this one, Archaeoscyphia looks really close to me. :cool: very cool, thanks for the link.
 

Architeuthoceras

Architeuthis
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#8
DWhatley;175264 said:
It seems strange that sponge can leave a fossil
I think the spicules actually hold things together and make a pretty good internal skeleton, a lot of structure to preserve or replace. 8-)

Terri;175276 said:
Thanks Kevin, I don't think I would ever have thought to search sponges on this one, Archaeoscyphia looks really close to me. :cool: very cool, thanks for the link.
A picture of that sponge is in almost every book on fossils I have read, nice to see someone actually find one. :heee:
 

Terri

Sepia elegans
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#10
Hey Kevin, can the title to this thread be changed? (since it's obviously not a gastropod). I couldn't figure out how to change it.I have more I'd like to post, I should probably do a lot more reading on sponges first though:banghead:...so much to learn!:bonk:
 

Mike Bauer

Vampyroteuthis
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#13
Terri;175179 said:
This ?gastropod is from the Bigby-Cannon Limestone in Smith Co. Tn. I've never found one like this and the closest I've found in my browsings is possibly in the Strombidae family? Not the best pictures but maybe there's enough there to point me in the right direction. It's about 3cm. across and a couple high. Any ideas?
So this a photo of a fossilized sponge? Like some others I don't see it! Is there any way you can highlight the sponge part of the rock in the photo? Any idea how old this rock is?
 

Terri

Sepia elegans
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#14

Mike Bauer

Vampyroteuthis
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#15
Interesting, as fragile as sponges are I would have thought they would decay before they could become fossilized. Are they in a clay or lava rock. Any other clues as to what happened just before they died and became part of the rock?
 

Architeuthoceras

Architeuthis
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Moderator
#16

Possible explanation of this fossil: The red outlines what looks like a root (? Holdfast, anchor ?, does anyone know how sponges anchor to the bottom?). The orange outlines a stem, and the yellow outlines the "flower". Perhaps there are two separate organisms here, or just the yellow is a sponge and the other something else.

The rock is limestone, it used to be limey mud. With all the other broken bits of echinoderms and shells, it was probably deposited at or near normal wave base and above storm wave base. If it is all one organism, it looks like a storm ripped it off the bottom and it was buried in the mud protecting it until it lithified.:twocents:
 

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Terri

Sepia elegans
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#17
:notworth:Thanks Kevin! i was wondering if the(?holdfast) was part of the fossil or not. I may be out that way in a few days and if I can find it again I'll try to get a few better pictures.
 

DWhatley

Cthulhu
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#18
The sponges that I have growning in my aquarium :grin: seem to attach in two different ways. The flatish ones that grow from within the rocks (and don't show up for a couple of years after the rock is in the aquarium) creep along the rock surface and stay low to the rock, smothering anything that might be growing there. I have another of this unplanted kind that grows out in a string but can't see the attachement. The more decorative ones I have purposely transplanted grow a new base downward (vs the ones in the rock that grow upward) that creeps onto/into the live rock rock but retains the main buldge in a blob. There is nothing I see in any of the ones I have had that resembles a separate holdfast or stem.
 

Terri

Sepia elegans
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#19
I've been googling all evening, and there are some papers on these sponges, but I only have access to the abstracts, and they don't tell me what I want to know. Now I'm really curious, it seems to me that when I found it, it appeared to be all one fossil. So I really hope I can find it, I have it narrowed down to about a 100 sq. ft. area:fingerscrossed:
 

Terri

Sepia elegans
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#20
I went out last week in search of the sponge, didn't have a lot of time and kept getting sidetracked by nautiloids! I know it's there somwhere.....
 

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