Spongy Joe Posted May 27, 2018 Share Posted May 27, 2018 9 hours ago, Tidgy's Dad said: Very nice! Sounds like a lot of work, but with all those new species very rewarding and exciting too. Yes, just a bit. This is what 'a lot of work' looks like in practice... We've had another week of fieldwork since then, and I'm not entirely sure where the fossils are going to go... 2 Link to comment Share on other sites More sharing options...
Spongy Joe Posted May 27, 2018 Share Posted May 27, 2018 And this is the most abundant sponge in the fauna: what we call 'finger sponges' (probably three species that look very similar), often found in dense masses and with very little preservation of the skeleton in most specimens due to having had very fine spicules. Although the basic form isn't unusual, nothing similar to them has ever been described before, from any age. It's a good thing I've got hundreds of them to work on... These ones are about 10 cm long. (For those with sharp eyes, yes, the round one at lower right is a different species.) 1 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted May 27, 2018 Share Posted May 27, 2018 Just now, Spongy Joe said: And this is the most abundant sponge in the fauna: what we call 'finger sponges' (probably three species that look very similar), often found in dense masses and with very little preservation of the skeleton in most specimens due to having had very fine spicules. Although the basic form isn't unusual, nothing similar to them has ever been described before, from any age. It's a good thing I've got hundreds of them to work on... These ones are about 10 cm long. (For those with sharp eyes, yes, the round one at lower right is a different species.) Very interesting. is this current alignment or how they grew? A bit of both, grew in masses and then flattened together? Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
Spongy Joe Posted May 27, 2018 Share Posted May 27, 2018 Yeah, a bit of both. They're often current-aligned, but also size-sorted, so you get dense forests of a particular age. They've clearly been knocked over, but they may not have travelled far except for that. We're thinking that the main burial mechanism was nepheloid layers: collapsing clouds of suspended mud. Transport doesn't seem to have been violent; we don't often see torn fragments of sponges, and when we do there's usually no soft tissue preserved, which suggests it was already dead before burial. Having said all that, there are differences from one bed to the next, and we get sponges through ten metres of rock, across ten kilometres, so there's a lot of scope for variety here! 2 Link to comment Share on other sites More sharing options...
Wrangellian Posted May 27, 2018 Share Posted May 27, 2018 Link to comment Share on other sites More sharing options...
rockofages Posted May 27, 2018 Share Posted May 27, 2018 I found this in Litchfield county CT. I think it might be a sponge. Link to comment Share on other sites More sharing options...
Spongy Joe Posted May 27, 2018 Share Posted May 27, 2018 Nice try, but no, sorry! Sponges aren't made of bubbles, and even the 'spongiest' sorts don't fossilise in anything like this way. This is artificial... my guess is some furnace slag that's been rendered with concrete for a garden wall. 2 Link to comment Share on other sites More sharing options...
doushantuo Posted May 27, 2018 Share Posted May 27, 2018 You must have had acting classes. ***"you call that "immersed in thought?".My dog is a better actor!**** Link to comment Share on other sites More sharing options...
Spongy Joe Posted May 27, 2018 Share Posted May 27, 2018 I was actually just trying to remember where I put that nice little Pirania... honest, guv! Link to comment Share on other sites More sharing options...
doushantuo Posted May 27, 2018 Share Posted May 27, 2018 I am also wondering if solitary standing waves orthogonal to the coast can be the cause of variability in nepheloid layer sedimentology,BTW. **Sunday afternoon,high humidity,stiflingly hot,mind starts to wander idly*** SEM of a choanocyte chamber of Spongilla : microvilli,flagellum,and collars are shown Link to comment Share on other sites More sharing options...
Spongy Joe Posted May 27, 2018 Share Posted May 27, 2018 Cute little Spongilla, with its full array of filtratory machinery (currently switched off due to excess of liquid nitrogen...). Of course, that's the sort of preservation I'd really like to have... Nepheloid layers: yes, of course. Any persistent patterns of water movement are going to affect the generation of suspended mud (and the initial buildup of sediment that can be remobilised), its transport pattern, or (to some extent) its deposition, depending on its position. The deposition is largely from mass flocculation and gravity fallout, of course, so a standing wave might not have much effect on that... although it might affect local density patterns and allow flocculation to occur more easily. Too many variables! And, alas, almost invariably beyond the resolution of the geological record, in any case... Link to comment Share on other sites More sharing options...
rockofages Posted May 27, 2018 Share Posted May 27, 2018 1 hour ago, Spongy Joe said: Nice try, but no, sorry! Sponges aren't made of bubbles, and even the 'spongiest' sorts don't fossilise in anything like this way. This is artificial... my guess is some furnace slag that's been rendered with concrete for a garden wall. I often think things I find are man made. Thank you for your info. Link to comment Share on other sites More sharing options...
Buzzard Posted February 10, 2019 Share Posted February 10, 2019 A few flint sponges from the upper chalk in Kent. I’m not an expert in identification, but the one I’m always baffled by is the one top right. I have a few of this type that have the parallel lines that also run vertically for a few millimetres. Any ideas 1 Link to comment Share on other sites More sharing options...
Wrangellian Posted February 11, 2019 Share Posted February 11, 2019 Nice ones - I'm not sure that I've ever seen flint sponges before so I can't help you, but I'm sure someone who can should be along soon. Link to comment Share on other sites More sharing options...
Ludwigia Posted February 11, 2019 Share Posted February 11, 2019 I'm afraid I can't helpyou myself, since I'm by no means in the know about chalk sponges, but maybe if you post a few sharp close-ups of the one in question, someone who might know could have a better look. @TqB ? 1 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
TqB Posted February 11, 2019 Share Posted February 11, 2019 Thanks, @Ludwigia - yes, closeup please! I don't think it's a sponge (the others are very nice!) - perhaps a bivalve fragment, maybe a Pinna where the ridges are virtually parallel. Tarquin Link to comment Share on other sites More sharing options...
Buzzard Posted February 17, 2019 Share Posted February 17, 2019 Thanks for the interest. The lines in this one are about 4cm long and then vertically about 4mm. I don’t know if it’s sponge related - just don’t know what they are really. The rest of the rock in the area is about 85-86 million years Link to comment Share on other sites More sharing options...
Wrangellian Posted February 18, 2019 Share Posted February 18, 2019 I think that one is the imprint of a piece of Inoceramus shell, I've got pieces very similar to that one from my contemporary (Santonian) deposits over here. Link to comment Share on other sites More sharing options...
Buzzard Posted February 18, 2019 Share Posted February 18, 2019 Thanks again. Looking through this topic Rastellum posted some similar pictures 16th April 2013 with a similar answer. The only further bit of info is that these are always flat. Link to comment Share on other sites More sharing options...
Adam86cucv Posted February 26, 2019 Share Posted February 26, 2019 This little fella arrived yesterday. Astreospongia from the Silurian Period. Seller said it was found in the Beech River Formation along a road-cut on Highway 641 in Decatur County, Tennessee. 2 Link to comment Share on other sites More sharing options...
connorp Posted August 4, 2019 Share Posted August 4, 2019 I'd like to give this topic another boost. Fossil sponges really are quite fascinating. Here are two (well 1 and a half I suppose) I recently acquired. Both from the Early Cambrian Chengjiang biota. This is Leptomitus teretiusculus. I am completely mesmerized by the purple color. This is a chancelloriid, I believe Allonnia sp. I said 1 and a half sponges because there's disagreement as to whether these are actually sponges. 1 Link to comment Share on other sites More sharing options...
TqB Posted August 4, 2019 Share Posted August 4, 2019 4 hours ago, connorp said: I'd like to give this topic another boost. Fossil sponges really are quite fascinating. Here are two (well 1 and a half I suppose) I recently acquired. Both from the Early Cambrian Chengjiang biota. This is Leptomitus teretiusculus. I am completely mesmerized by the purple color. This is a chancelloriid, I believe Allonnia sp. I said 1 and a half sponges because there's disagreement as to whether these are actually sponges. Lovely! I asked sponge specialist @Spongy Joe about chancellorids and he reckons that they definitely are sponges. Tarquin Link to comment Share on other sites More sharing options...
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