tag:blogger.com,1999:blog-5460788270738656369.post2023521498636225935..comments2023-12-24T07:02:43.274+08:00Comments on Catalogue of Organisms: Prototaxites: A Giant that Never Was?Christopher Taylorhttp://www.blogger.com/profile/11075565866351612441noreply@blogger.comBlogger43125tag:blogger.com,1999:blog-5460788270738656369.post-85832564685435333372016-03-04T10:01:36.818+08:002016-03-04T10:01:36.818+08:00I don't think anyone has ever suggested Protot...I don't think anyone has ever suggested <i>Prototaxites</i> as a fleshy mushroom, the polypore model has always been the way to go. And you're quite right that the feeding hyphae might not be preserved as readily as the reproductive structure, but the question raised above is whether a diffuse 'root-system' of soft hyphae would be adequate to root the structure in place. As noted <a href="http://coo.fieldofscience.com/2012/11/prototaxites-revisited.html" rel="nofollow">elsewhere</a>, it has been suggested that associated fossils may be <i>Prototaxites</i> 'roots' (actually rhizoids) but the evidence is not conclusive. Conversely, nothing like the 'liverwort rolls' exists in the modern world (as far as I know), but then nowhere in the modern world has an environment like the terrestrial Silurian.<br /><br />In terms of nutrient availability, I don't think we should assume <i>a priori</i> that there was little available organic matter to feed on. Mosses and liverworts could still be producing dense ground-covers that might provide a lot of nutrients for associated saprobes, especially if each <i>Prototaxites</i> individual's hyphal system covered a very large area.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-24531747466262285712016-03-04T00:25:05.423+08:002016-03-04T00:25:05.423+08:00Prototaxites: the Silurian Enigma that just won...Prototaxites: the Silurian Enigma that just won't die!<br /><br />Of course this is all educated guesswork. Rather than thinking of this structure as a fleshy mushroom (unlikely) why not some sort of proto-polypore? The sturdy, thick-walled skeletal hyphae of those wood decay fungi are much more robust than mere thin-walled hype like are found in our modern day mushrooms, and certainly more robust than modern day liverworts. Even those hard, perennial structures are supported by other feeding sorts of hyphae, and those are not "woody" or easily fossilized. In other words, a fungal "support system" underground would not be likely to turn to stone over time, or leave impressions in mud.<br /><br />But if not photosynthetic, what the heck was this thing eating? Modern day fungi eat organic debris, and it would take an awful lot of it to make a perennial structure of this size. <br /><br />More on the polypore model: many polypores have perennial fruit bodies, which persist in the environment for years. Many polypores incorporate plant debris into their bodies as they grow. That would also account for the plant material that is sometimes found in these Prototaxites structures.<br /><br />The liverwort theory is certainly interesting. Does this actually happen in modern times? Are there examples that we can view? One problem is that cross-sections reveal some random placement of layers, not a discrete tree ring model nor a rolled spiral model.<br /><br />But who knows what they really were, other than a great topic for scientific speculation!? debbie viesshttps://www.blogger.com/profile/03893239783109004957noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-63083908607419950002015-06-29T07:26:02.339+08:002015-06-29T07:26:02.339+08:00Years ago, I saw a large "trunk" of Prot...Years ago, I saw a large "trunk" of Prototaxites eroded and later dug from a hillside. The "trunk" was distinctly tree-like and, in my estimation, in no way was that a rolled-up mat of anything. It was a discreet and separate entity with an integrity of its own. I made thin sections of this specimen, and the "tubes" weren't like anything from a liverwort. Neither liverwort anatomy nor Prototaxites anatomy is a mystery. While no explanation of Prototaxites has ever really made sense, that it would be balled-up liverworts makes the least sense of all to me.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-64838550495233700922014-04-17T04:27:54.708+08:002014-04-17T04:27:54.708+08:00It seems unlikely. Large fungi can produce quite s...It seems unlikely. Large fungi can produce quite sturdy hyphal 'roots' (rhizomorphs is the accurate term).Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-50320534158191807302014-04-15T09:06:01.031+08:002014-04-15T09:06:01.031+08:00Good question, I have no idea. Maybe they were ver...Good question, I have no idea. Maybe they were very "soft" and small, decaying in almost no time at all?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-79422680659284633622014-04-05T17:17:39.942+08:002014-04-05T17:17:39.942+08:00I've been thinking about cramp balls (Daldinia...I've been thinking about cramp balls (Daldinia concentrica) - a fungus also made up of concentric layers resembling rounded globs of charcoal and with a similar consistency. You can even use them for kindling. They're much smaller than our enigmatic fossil organisms of course and they grow on dead wood, but still... It makes you think about the diversity of fungi.Steve Lawhttps://www.blogger.com/profile/04939837731535127700noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-40693927541795886292014-04-03T22:34:43.867+08:002014-04-03T22:34:43.867+08:00The question then becomes, where are the fossils o...The question then becomes, where are the fossils of the <i>Prototaxites</i> 'root' system? I've noted in a <a href="http://coo.fieldofscience.com/2012/11/prototaxites-revisited.html" rel="nofollow">subsequent post</a> that one group of authors has tentatively identified such a system, but it's still not conclusive.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-25241999710531887582014-04-03T07:51:41.717+08:002014-04-03T07:51:41.717+08:00Just a few thoughts on a long dead post. You might...Just a few thoughts on a long dead post. You might be able to think of Prototaxities as a saguaro. Some people commented that the large winds of the Silurian would have blown over a structure like Prototaxities. Saguaros are often found in windy conditions and have no taproot, but a large branching root system that radiates almost instantly once in the ground. If Prototaxities was a fungus it could be similar, with branching hyphae spreading across the marshes to feed on decaying matter but no deep taproot. The immense height of the structure might not be so much as something that was a deliberate advantage over the early plants, but a effect of its growth. Prototaxities could have taken hundreds of years to grow, slowly adding cells to the (already mature?) fruiting body (it's not like it going to think, Oh, I'm tall enough, time to stop growing!). Saguaros similarly take hundreds of years to grow. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-35025423439349711622012-11-04T07:18:42.015+08:002012-11-04T07:18:42.015+08:00The address is at the top right of this screen: ge...The address is at the top right of this screen: gerarus at westnet.com.au.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-13560817542031850162012-11-03T18:14:32.170+08:002012-11-03T18:14:32.170+08:00Hi Chris,tried emailing you, but came back as unde...Hi Chris,tried emailing you, but came back as undeliverable. It was the email address I found in your HomePage. Richard Bizleyhttp://www.bizleyart.comnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-46913921551788118152012-11-01T22:19:11.352+08:002012-11-01T22:19:11.352+08:00Hi Chris, yes that's fine, thanks.Hi Chris, yes that's fine, thanks.Richard Bizleyhttp://www.bizleyart.comnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-57088295040244818432012-11-01T16:31:45.967+08:002012-11-01T16:31:45.967+08:00Nice - it's a wonderfully surreal and atmosphe...Nice - it's a wonderfully surreal and atmospheric landscape.<br /><br />Just noticed i've been miss-spelling Prototaxites up until now. Oops.Steve Lawhttps://www.blogger.com/profile/04939837731535127700noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-34785988680468395492012-11-01T10:49:52.254+08:002012-11-01T10:49:52.254+08:00Looks nice, Richard. Could I use it for a post her...Looks nice, Richard. Could I use it for a post here?Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-54710598265692196102012-10-31T20:27:16.984+08:002012-10-31T20:27:16.984+08:00Please have a look at my new painting, and I shall...Please have a look at my new painting, and I shall be interested in your comments. I decided to keep it fairly simple, but yet atmospheric.<br /><br />http://www.bizleyart.com/gallery/prehistoric/palaeozoic/devonian/1225b-prototaxites-207<br /><br />Richard Bizleyhttp://www.bizleyart.comnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-28818868945260567662012-10-24T22:40:59.620+08:002012-10-24T22:40:59.620+08:00I think what I will do is to carry on with the pai...I think what I will do is to carry on with the painting. When done, I'll show it to you all. You can then critique it. I've sketched it and it is just so bizarre seeing these towering structures, it looks science fiction. I tell myself to look'outside the box' and try and base it on what information we have.<br />Watch this space ...<br />Richard Bizleyhttp://www.bizleyart.comnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-63325044739714091202012-10-24T09:29:12.102+08:002012-10-24T09:29:12.102+08:00Steve, Richard - sorry about being slow replying, ...Steve, Richard - sorry about being slow replying, I was trying (largely unsuccessfully) to look up some further details. In response to Taylor <i>et al.</i>'s critique of the rolled liverwort proposal, be sure to read Graham <i>et al.</i>'s counter-response (<a href="http://www.amjbot.org/content/97/7/1079.abstract" rel="nofollow">http://www.amjbot.org/content/97/7/1079.abstract</a>). At the very least, if <i>Prototaxites</i> did indeed grow as a single column, it did not grow in the same manner as a modern tree, because the growth rings are not as evenly concentric.<br /><br />Known <i>Prototaxites</i> specimens appear to have largely been subject to transportation before burial, so we don't seem to have any direct evidence of the growth environment. I don't think that bryophyte mats are incapable of forming complex environments, but I suspect that it's likely to be soil-based rather than aerial.<br /><br />As regards the animals to be found in such an environment: first off, I don't think that there is any evidence of terrestrial molluscs until some time later (feel free to correct me if I'm wrong). Molluscs, even from that long ago, have a relatively high preservation potential, so an apparent absence is likely to correspond to an actual absence. Shell-less molluscs like slugs, of course, have less of a fossil record (if any), but it seems very unlikely that terrestrial slugs would have evolved when terrestrial snails (for which, having shells, desiccation in the terrestrial environment is less of a problem) had not.<br /><br />What we do have direct evidence for at the time is arthropods, particularly <a href="http://en.wikipedia.org/wiki/Euthycarcinoidea" rel="nofollow">euthycarcinoids</a>. I think it most likely that any Silurian terrestrial animals, like euthycarcinoids, are likely to be amphibious: mostly aquatic, but making forays out of the water for feeding/breeding/etc. Kind of like hippos.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-9544455594073893782012-10-23T17:42:47.825+08:002012-10-23T17:42:47.825+08:00Hi Steve
(Yes I got my email thanks).
Thanks also ...Hi Steve<br />(Yes I got my email thanks).<br />Thanks also for thinking about my project.<br />To readers of this foram, I am currently thinking of creating a scene containing some Prototaxites (very few images of these organisms have been shown, no doubt due to lack of information). I am sorely tempted to paint clumps of them growing rather than isolated ones, possibly some fallen ones being consumed etc. I am painfully aware of the balance between fanciful scene & academic, due to lack of references. I do like Steves idea of having some aquatic animals foraging briefly on the land . Anyway, the idea is to show a scene with a rising sun, lakes etc dots the land, show clumps of Prototaxites amongst the morning mist with perhaps some sign of animal life on the water margins. Perhaps have the lower part of Protoaxite being consumed, showing some damage, leaving the tops untouched due to their great heights. Do you think this'll work? My burning question is do you think it is acceptable to paint them in clumps?<br />Thanks<br />RichardRichard Bizleyhttp://www.bizleyart.comnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-39748177669936926972012-10-20T16:24:03.704+08:002012-10-20T16:24:03.704+08:00Hi again Richard. I assume you got my email.
For ...Hi again Richard. I assume you got my email. <br />For readers of this forum I said "I can't tell you what to put in your picture. My comment was purely speculative. I'm always intrigued by the twin thoughts that the speed of evolution is so vastly underestimated by most people (and the time spans so enormous), and that fossilisation is so vanishingly unlikely, and therefore we can have absolutely no knowledge of almost all of what must have been there. Your picture, if you use my ideas, must be almost total science fiction."<br />I've been thinking about your project some more though. I assume you've had a look at a comprehensive inventory of fossils from the period to give you as many ideas as possible. My understanding (which may well be out of date now) is that most of the modern phyla were already there in the Cambrian - molluscs, arthropods, chordates, cnidaria etc etc but not in their familiar modern forms. For example, I understand that what we think of as typical molluscs (snails, clams and squid for example) didn't evolve until much later. Back then, the molluscs might have been more closely related to the segmented chitons for example, which might have occupied a much broader range of niches (huge carnivorous freshwater chitons? Planktonic swimming chitons? Shell-less slug-like chitons? Who can say?) plus there would also almost certainly have been other groups of molluscs that are completely extinct now, occupying the niches of modern molluscs and just as diverse in form (though presumably we'd have some fossil evidence of shelled animals so maybe this is not a good example). Remember that scaley limpet-like Burgess Shale animal? <br />Even worse, a lot of the niches occupied by modern molluscs were probably occupied by completely unrelated organisms which may be all but extinct now. An obvious later example is the brachiopods. There are quite a few extant small obscure groups, such as the Priapulids which were almost certainly much more important back then, and others, like the graptolites and conodonts that we know almost nothing about now, but which would also have been representatives of huge diverse groups. And there will be other groups, whole phyla even, of which there is not a trace now. This would have been true for all the groups, plants, animals, fungi and microbes. <br />Even so, my guess is that a lot of the niches would have been similar and a lot of the forms taken to fill them would have been familiar, so there would, in your scenario, almost certainly have been some sort of worm-like organisms, slug and limpet-like organisms, sessile bryzoan/sponge-like organisms, finned fish-like organisms and shrimp or centipede-like arthropods of some sort. So you can go ahead and paint some of these and I think, stand a fair chance of being right.<br />Hope this helps. ;-)Steve Lawhttps://www.blogger.com/profile/04939837731535127700noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-23684456138446655522012-10-19T17:29:19.100+08:002012-10-19T17:29:19.100+08:00I am an artist painting mainly scientific illustra...I am an artist painting mainly scientific illustrations and I was about to do a painting of these enigmatic organisms. I have read this topic with interest and I have to say Steve Law paints a very persuative argument that fits with my thinking. I happened to Google for Prototaxites images and was amazed how few there were (though not surprising of course, as not enough is know about them). <br />I thought before starting, I should ask if there's anything I should be aware of before commencing. To see the sort of art I do, please have a look at my website (http://bizleyart.com)<br />I proposed a painting of an area of boggy tidal shoreline biota with animal life eg arthropods mollucs etc. So what would you like to see on this painting I propose? (Be aware that my painting is of course my own copyright) I just thought you'd be interested to see how I would develope into something we all can visualise.<br />Richard Bizleyhttp://www.bizleyart.comnoreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-3310577736012461522012-07-29T16:29:11.121+08:002012-07-29T16:29:11.121+08:00Thanks Andreas - the AmJBot article seems to neatl...Thanks Andreas - the AmJBot article seems to neatly get shot of the lichen mats hypothesis.<br />Extra height in 'plants' btw doesn't have to be about photosynthesis. It can also be about avoiding predators or competitors, or spore/seed dispersal.<br />Our thought experiments so far seem to have imagined a rather boring, lunar landscape with nothing but a 2 dimensional flora of lichens, liverworts and maybe algae (indeed the lichen mats hypothesis depends on such a flat barren species-poor environment for its plausibility) but there's nothing to say there wasn't a dense and diverse community of something resembling mosses or charophytes possibly of considerable depth - especially in wet and sheltered sites - gullies, wet seeps or tidal marshes, perhaps forming a thick peaty soil in some places. There could have been epiphytes and climbers, and all manner of semi-terrestrial molluscs, arthropods and worms (and fish - why not? There are tiny catfish, gobies and eels that spend considerable amounts of time crawling about among wet litter and moss along the edges of streams and swamps these days.) All this is speculation of course, and I doubt the fossil record will help with such a boneless, lignin-free biota, but it seems to me that it might nevertheless help to visualise Protaxites in a much richer and more varied ecosystem than we have been, to really understand the possibilities.Steve Lawhttps://www.blogger.com/profile/04939837731535127700noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-27298101088449092412012-07-29T07:31:13.312+08:002012-07-29T07:31:13.312+08:00Sorry, Andreas, your comment went into the site...Sorry, Andreas, your comment went into the site's span filter and I've only just noticed that it needed to be freed.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-53911742119711841002012-07-04T15:40:04.719+08:002012-07-04T15:40:04.719+08:00I chanced across a paper disputing the liverwort m...I chanced across a paper disputing the liverwort mat hypothesis:<br /><br /><br />The enigmatic Devonian fossil Prototaxites is not a rolled-up liverwort mat: Comment on the paper by Graham et al. (AJB 97: 268–275)<br /><br /> Thomas N. Taylor,<br /> Edith L. Taylor,<br /> Anne-Laure Decombeix,<br /> Andrew Schwendemann,<br /> Rudolph Serbet,<br /> Ignacio Escapa, and<br /> Michael Krings<br /><br /><br />http://www.amjbot.org/content/97/7/1074Andreas Johanssonhttps://www.blogger.com/profile/08802392912541974977noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-83853596066513202412012-06-25T02:27:30.963+08:002012-06-25T02:27:30.963+08:00Maybe you're thinking too literally as to the ...Maybe you're thinking too literally as to the nature of liverwort mats. <br /><br />Instead think of other sorts of obviously more advanced plants of today take advantage of their growing season, wind, like tumbleweeds.<br /><br />During the wet season tumbleweeds sprout, grow fast to take advantage of the wet season in the semi-arid regions they live. <br /><br />By the time the dry season arrives the plant is ready and top heavy with seeds ready to be spread.<br /><br />Quickly the root drys out and it breaks releasing the tumbleweed to blow in the wind and spread its seeds. <br /><br />While liverworts don't have seeds to spread they do have their spores which would have needed space on the ground to sprout and start the next generation, but they have to wait until the growing season is over, and the dry season sets everything up for the next generation to grow.<br /><br />Being liverworts, it wouldn't take very long for the dry season winds to desiccate all the many acres of liverworts and other primitive plants with no way to prevent it. <br /><br />Once dried enough, even light winds with an occasional strong gust to get things going would probably be able to lift them up off the ground it's much easier to imagine the wind rolling them up. <br /><br />The rolling up also conveniently clearing the ground for next season's growth. <br /><br />The notion of strong winds ripping up vital, very green liverworts during the growing season requires a much more complex set up.<br /><br />Simply factoring in a wet season/dry season semi-arid climate modeled on the ones we have today brings all the factors necessary together to make this theory sound very sensible. <br /><br />I'm sure as you know most such climates feature hot dry winds sometime during the year.<br /><br />As for the rolls, even though they were dessicated, they still had some moisture in them, far more than the surrounding area during the dry season, enough for fungus to grow within them and prevent them from being completely dried out and easily destroyed completely without a trace.Johnn Moraleshttps://www.blogger.com/profile/18410754869779549100noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-85722751325232158192012-04-27T17:53:26.205+08:002012-04-27T17:53:26.205+08:00Nice to see this debate is still going on after al...Nice to see this debate is still going on after all this time. It's been rumbling about in my brain since I heard about these things a few months ago. It feels like an appropriately slow rate of development. I was trying to think of analogous modern organisms and the Saguaro cacti were the obvious candidates. I'm not sure if these evolved their form originally to compete with other tall vegetation (ie trees) or for some other reason, but a columnar lichen - steadily adding layers each wet season, forming a tough fibrous 'trunk' (incorporating epiphytes as it goes) suddenly seems a lot more plausible. Tree-fern caudices would be another parallel. I imagine the hyphae/rhizoids/novel root-like structures evolving to be as substantial as the upright part (like the wide root-plates of the cacti - absorbing dew and cloudbursts quickly over a wide area) I'm also imagining fruiting bodies forming seasonally (as cactus flowers do) on the upper part of the column. <br />My only problem is what the immature specimens would look like. Cacti first expand to the the full diameter close to ground level and only then go up - hence no growth rings. Protaxites would have to start as a sapling. <br />Of course it's all conjecture...Steve Lawhttps://www.blogger.com/profile/04939837731535127700noreply@blogger.comtag:blogger.com,1999:blog-5460788270738656369.post-50878716648704971852012-04-18T07:09:16.860+08:002012-04-18T07:09:16.860+08:00I thought the idea was that (despite the lack of o...<i>I thought the idea was that (despite the lack of other evidence) Prototaxites was a lichen, so it would have needed light?</i><br /><br />I think most of the <i>Prototaxites</i>-as-fungus reconstructions I've come across have compared it to a bracket fungus (so it would be a perennial fruiting body), not a lichen.Christopher Taylorhttps://www.blogger.com/profile/11075565866351612441noreply@blogger.com