Jerry W. Posted March 31, 2020 Share Posted March 31, 2020 I would welcome any help identifying a fossil that I suspect to be some sort of bacteria/coral/sponge/aquatic item. Sorry to sound so ignorant about it, but I really don't know aquatic life by sight. The fossil is 6 cm long X 4 cm tall X 2 cm thick. Found in an Upper Cretaceous area, Kirtland Formation of northwestern New Mexico. The fossil has the small pits located around the edges and on the opposite side too. Thanks! Link to comment Share on other sites More sharing options...
Spoons Posted March 31, 2020 Share Posted March 31, 2020 My mind’s telling me coral... But my body... My body’s telling me Bryozoan. Link to comment Share on other sites More sharing options...
caldigger Posted March 31, 2020 Share Posted March 31, 2020 I was aiming toward sponge. What does the broken end look like? 2 Link to comment Share on other sites More sharing options...
Jerry W. Posted March 31, 2020 Author Share Posted March 31, 2020 24 minutes ago, caldigger said: I was aiming toward sponge. What does the broken end look like? It is not very defined, but the broken area appears to have a continuation of the cell-type structure going through that portion as well. In looking at sponge photos online, I believe what I'm seeing something with this fossil that is quite similar to the attached photo. Pardon my terminology since I don't know the proper names, but in each pit or dimple, there seems to be a center protruding core. 1 Link to comment Share on other sites More sharing options...
caldigger Posted March 31, 2020 Share Posted March 31, 2020 So likely a coral as Spoons suggested. 1 Link to comment Share on other sites More sharing options...
Jerry W. Posted March 31, 2020 Author Share Posted March 31, 2020 35 minutes ago, caldigger said: So likely a coral as Spoons suggested. Yes, it would seem so. Thank you, fellas! Link to comment Share on other sites More sharing options...
digit Posted March 31, 2020 Share Posted March 31, 2020 It looks way too irregular (in my mind) to be coral which tends to be much more geometrically patterned. The coral skeleton produced by a coral polyp is called a corallite and is in the shape of a cup called a calyx surrounded by a wall called a theca. Within the calyx are usually several blades (septa) radiating out from the center and many corallites have a central "protruding core" called a columella ("small column"). Unless this is very highly eroded I'm not seeing signs of it being coral. @caldigger requested a close-up of the broken end and I too am curious to see this piece in cross-section as it would give a good idea to its structure that cannot be seen face on. Corals grow by laying down microscopic amounts of calcium carbonate daily and slowly build their platforms upward leaving linear tracks behind them that are very obvious in cross-section. Cheers. -Ken 2 Link to comment Share on other sites More sharing options...
Jerry W. Posted March 31, 2020 Author Share Posted March 31, 2020 1 hour ago, digit said: It looks way too irregular (in my mind) to be coral which tends to be much more geometrically patterned. The coral skeleton produced by a coral polyp is called a corallite and is in the shape of a cup called a calyx surrounded by a wall called a theca. Within the calyx are usually several blades (septa) radiating out from the center and many corallites have a central "protruding core" called a columella ("small column"). Unless this is very highly eroded I'm not seeing signs of it being coral. @caldigger requested a close-up of the broken end and I too am curious to see this piece in cross-section as it would give a good idea to its structure that cannot be seen face on. Corals grow by laying down microscopic amounts of calcium carbonate daily and slowly build their platforms upward leaving linear tracks behind them that are very obvious in cross-section. Cheers. -Ken This fossil is odd. If I had to guess, and I really am, I would say it appears to be composed of sand compressed into a mold of a cast of the original coral. If I am describing it accurately, such a process would explain why the fossil doesn't have very distinctive impressions. I can try to get some better photos for you to look at, but it requires side-lighting that is just right for a photo to show what I am seeing. Link to comment Share on other sites More sharing options...
digit Posted March 31, 2020 Share Posted March 31, 2020 A cast is certainly possible. And there is some vague patterning to it but I'm not really seeing the regularity that might indicate coral (or a coral cast). Definitely, more difficult to pin down if you are working with an impression and not the fossil itself. Cheers. -Ken Link to comment Share on other sites More sharing options...
Spoons Posted March 31, 2020 Share Posted March 31, 2020 11 hours ago, digit said: there is some vague patterning to it but I'm not really seeing the regularity that might indicate coral (or a coral cast). Definitely, more difficult to pin down if you are working with an impression and not the fossil itself. Now that its morning and I'm a bit more coherent I think i may be inclined to agree with you. If it were a mold of a coral I think we could expect it to be more geometrically regular as you previously stated. Picture #1 indicates coral to me much more than Pic #2. If this specimen is purely a result geological processes, what are those responsible? Link to comment Share on other sites More sharing options...
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