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Weirdie
Jan 26, 2015 16:03:59 GMT -5
Post by Joe Botting on Jan 26, 2015 16:03:59 GMT -5
Here's another from the vaults. It's encrusting on a fragment of orthocone nautiloid shell (a rare thing at that site).
 [nautiloid fragment roughly 25 mm wide]
The bryozoan is nice and obvious at the lower right of the encrusting mass, as is the Schizocrania brachiopod at lower left of the frame. The rest of the encrustation is a tad weird, though. There is a cemented valve of Schizocrania forming the margin at the top, but overlying and extending down to the regularly-branching bryozoan is a weird texture that looks like bryozoan but isn't (as far as I can tell). It's too fine, and too irregular. It doesn't seem to have any continuous tubes in the structure, and nothing really bryozoan-like:
What is it? Algal or bacterial colony, perhaps? I've not seen anything like it and am really not sure...
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Weirdie
Jan 29, 2015 1:28:46 GMT -5
Post by ammocarbsteve on Jan 29, 2015 1:28:46 GMT -5
Hi Joe.... It is very unusual....I cant say what it is either but I can say what I have found that had a similar patternation...Rhizodont scales...
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Weirdie
Jan 29, 2015 18:04:45 GMT -5
Post by Joe Botting on Jan 29, 2015 18:04:45 GMT -5
Hi Joe.... It is very unusual....I cant say what it is either but I can say what I have found that had a similar patternation...Rhizodont scales... Thanks Steve. I always like odd comparisons with textures and the like, even if there's blatantly no phylogenetic relationship..! There was a good talk at Pal Ass about the setae of the Burgess Shale brachiopod Micromitra acting as camouflage on it's preferred host of Pirania sponges. Can't think what rhizodonts can tell us here, but there could potentially be some hydrodynamic analogy. Or, as Lucy would say, it might just be random.  |
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Weirdie
Jan 30, 2015 9:43:56 GMT -5
Post by ammocarbsteve on Jan 30, 2015 9:43:56 GMT -5
Joe.... The remains shape almost have some symmetry... Very strange...
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tqb
Enthusiastic fossilologist
Posts: 111
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Weirdie
Feb 9, 2015 15:04:08 GMT -5
Post by tqb on Feb 9, 2015 15:04:08 GMT -5
I like that - I've seen similar markings on belemnites but they're internal of course... perhaps it's an endocone with later encrustation  |
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Weirdie
Feb 10, 2015 6:14:25 GMT -5
Post by Joe Botting on Feb 10, 2015 6:14:25 GMT -5
Cheers both - and a curious observation, Tarquin! I doubt it's an endocone, to be honest (based on the size), but it's worth considering some sort of biological property of the nautiloid itself...
On closer look, it seems not. The preservation is apparently organic, and it seems to overlie both the cemented brachiopod valve and some of the bryozoan colony. Until you suggested that, I hadn't thought to check!
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tqb
Enthusiastic fossilologist
Posts: 111
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Weirdie
Feb 10, 2015 8:44:07 GMT -5
Post by tqb on Feb 10, 2015 8:44:07 GMT -5
Oh, well, didn't really think so!
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Weirdie
Mar 25, 2015 5:11:48 GMT -5
Post by pleecan (Peter Lee) on Mar 25, 2015 5:11:48 GMT -5
 Reprocessed. Inverted colour. |
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Weirdie
Mar 25, 2015 5:22:04 GMT -5
Post by pleecan (Peter Lee) on Mar 25, 2015 5:22:04 GMT -5
 inverted colours. |
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