Post AsNNvxkCwANN8EhqE4 by grb090423@mastodon.social
(DIR) More posts by grb090423@mastodon.social
(DIR) Post #AsNNgw0z5K19QNO4yu by futurebird@sauropods.win
2025-03-24T09:59:59Z
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Whenever people discuss the majestic giant griffinflies of the Carboniferous, or the remarkable millipede and tank tread come to life, Arthropleura they also like to say "But O2 levels were higher then, and that is why invertebrates could grow so large." the implication being that such creatures could never live today, they are from an alien Earth separated from us not just by time but by the fundamental structure of the ecosystem. Increasingly I think this is just a comforting lie. 1/
(DIR) Post #AsNNvxkCwANN8EhqE4 by grb090423@mastodon.social
2025-03-24T10:02:40Z
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@futurebird Looking forward to the rest of this thread. I know it'll be hugely interesting 👍
(DIR) Post #AsNNxQjIeiijJlytwe by futurebird@sauropods.win
2025-03-24T10:02:59Z
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Consider Meganeuropsis permiana. This was the largest griffinfly to ever live. (Griffinflies are very similar to dragonflies, to call Meganisoptera "giant dragonflies" isn't strictly correct, although most of their morphology is very similar) And it's right there in the name: this bug is from the Permian NOT the Carboniferous! Likewise Arthropleura fossils can be dated to both periods of high and low O2. The hypothesis that high O2 is required for massive bugs seems unsupported. 2/
(DIR) Post #AsNOL07bEfG5kDaR9s by futurebird@sauropods.win
2025-03-24T10:07:14Z
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And it was only just a theory. But, it gets repeated so often it's exhausting. Limitations on the size of land-dwelling arthropods probably have more to do with complex selective pressures. Molting and metamorphosis are also issues. Consider the questions: Why are the largest flying mammals (bats) so much smaller than the largest birds? And why are the largest birds so much smaller than the largest pterosaurs? It's not a simple question. No one would try to say it's just one factor! 3/3
(DIR) Post #AsNOZ6pn4fvGcMz4Nc by david_chisnall@infosec.exchange
2025-03-24T10:09:44Z
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@futurebird I presume the scalability problem for most such creatures is that they don't have a heard and lung system and so need to absorb their oxygen directly, which limits their volume based on their surface area? Presumably something that increased airflow could help here, but there's also no reason that such a system or organs wouldn't evolve if necessary for larger sizes: It's not like it hasn't happened before (including in other arthropods).
(DIR) Post #AsNP09D8LYRdo6nNS4 by futurebird@sauropods.win
2025-03-24T10:14:40Z
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Could I be invested in this because people keep saying "ants that large are not realistic, O2 levels are too low to support apple-sized ants."Maybe. It's possible. Consider the coconut crab. I need say no more. Arthropods can be very large. They are not as successful as vertebrates when they are large for a variety of reasons, but apple-sized hyper intelligent space ants are perfectly reasonable. Heck, let's have basketball-sized ants. Why not!
(DIR) Post #AsNPE2VK4vaN3qvYq8 by futurebird@sauropods.win
2025-03-24T10:17:11Z
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And I just want to add, that in these trying times, I think that we could really use some basketball-sized ants.
(DIR) Post #AsNPUT8AqhXaH8vxjM by futurebird@sauropods.win
2025-03-24T10:19:06Z
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@u0421793 This is a fascinating way of looking at it since 19th century (and some 20th century) naturalists were convinced of the opposite.
(DIR) Post #AsNPqi3w0wWkxKYY4m by david_chisnall@infosec.exchange
2025-03-24T10:24:06Z
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@futurebird Space ants bring in a whole other dimension. As I recall, endoskeletons are easier to scale to large sizes because they support more of the internal structure. A large exoskeleton ends up with all of the organs supported by soft tissue in tension, whereas an endoskeleton can support them with a mixture of tension and compression over smaller distances (I seem to recall crabs have quite complex cartilage structures to try to mitigate some of this).If you're not limited to things that have evolved on Earth, there's no real reason that the endo vs exoskeleton split needed to happen. Especially if endoskeletons evolved first, I can imagine a structure that looks like an ant but with internal buttressing that would scale to at least the size of a small tank without too much trouble.And that, of course, is assuming Earth gravity. There's probably a lower bound on the gravity in which anything large and ant-shaped could evolve (very low gravity, I'd expect to favour things more like slime moulds, or balloons if the atmospheric pressure is high enough - why waste matter on evolving an internal structure if you don't need to support your weight?), but it's almost certainly much lower than here. A 0.1g planet could support much larger ants even without an endoskeleton. And then, if they're spacefaring for a long time, they may even lose some exoskeletal mass as well. Which would mean that we'd be safe from invasion: they'd implode if they managed to land on Earth.
(DIR) Post #AsNTV4cZrOzmMmhNTs by noodlemaz@med-mastodon.com
2025-03-24T11:05:01Z
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@futurebird there was a game I had on Amiga in the 90s, "IT! Came from the desert" - which had bus-sized ants.Bizarre.https://en.m.wikipedia.org/wiki/It_Came_from_the_Desert
(DIR) Post #AsNUUFomqRUol2aBc0 by llewelly@sauropods.win
2025-03-24T11:16:09Z
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@futurebird 1/3I agree with most of you're saying; most things are not well-explained by "one big reason" type answers, and the large size of either griffinflies or arthroplueroid millipedes probably isn't entirely about high O2. But for pterosaurs, there probably is one big factor that gave them a major advantage over birds, even if it isn't the whole story:
(DIR) Post #AsNV8tzCv7Agv6q5ia by oldclumsy_nowmad@mastodon.social
2025-03-24T11:23:26Z
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@futurebird Good idea! But why limit the concept? How about ants the size of those in the movie Them!. Or tiny ants with ganglia that can interface with USB connectors? Then the little guys could seize control of giant boring machines, use them to undermine SpaceX facilities, and save the World. Sorry! I get carried away sometimes. It's fun to imagine monsters that are more wholesome than the human kind.Thanks for your posts, which are thoughtful and fun to read!
(DIR) Post #AsNXK8WPPxM75wqzSa by sophieschmieg@infosec.exchange
2025-03-24T11:47:53Z
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@futurebird there are reasons for that, from a biomechanical point of view, based on respiration and liftoff mechanics:Pterosaurs and birds use a much more efficient breathing apparatus with air sacks, that use a counterflow exchange to get a continuous, highly efficient stream of oxygen.Bats instead use the mammal type sack lungs, which do neither continuous nor counterflow oxygen exchange, as that is an archosaur exclusive.Pterosaurs and bats both use their wing musculature for liftoff as well as sustaining flight, as opposed to birds, which use their leg muscles for liftoff, in other words they jump, whereas pterosaurs slammed their wings into the ground. Bats usually lift off by dropping from their perch, since they have next to no ground mobility, but can also lift off using their wing muscles when on the ground. So from what I can tell, by having an inefficient mammalian breathing apparatus on the one hand, and feathers forming wings forcing the use of legs to lift off on the other, we have locked ourselves out of having flying giraffe sized animals. Which is a pity.
(DIR) Post #AsNYD4bTgfCCrzQ8ES by leguinian_utopia@union.place
2025-03-24T11:57:48Z
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@futurebird I wanna pet one (if ants would be okay with being pet)
(DIR) Post #AsNYbksOAZp2vV6F0a by futurebird@sauropods.win
2025-03-24T12:02:18Z
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@noodlemaz "It came from the desert" has a nice rhythm.it came from the desertand it ain't going backya'll screwed up the weathernow them ants are STACKEDlet man take the measureof his deeds (They're wack)and the ants get the betterwith the sense men lack.prattle on your networksget ant-hackedBold and vocalyelling on 'Truth' Socialapes miss the patternBecause the truth's eusocialprattle on your networksget ant-hacked
(DIR) Post #AsNYiOMOHZ1v7ZIVKi by Phosphenes@mastodon.social
2025-03-24T12:03:25Z
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@futurebird If an exoskeleton was made of geodesic struts, could it scale like an endoskeleton? IE a 'buckyskeleton'. Moulting would not be necessary because the struts could elongate in place.
(DIR) Post #AsNYujh4n37slFrKHg by futurebird@sauropods.win
2025-03-24T12:05:41Z
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@leguinian_utopia Since ants groom each other, there should be some way to pet an ant. Here is a video I too of my carpenter ant queen (I still have this colony it's my oldest)I think she is enjoying being cleaned by her daughters. https://www.youtube.com/watch?v=3UcSAcYd8Qs
(DIR) Post #AsNZ3ScrcMD2Qr36KO by llewelly@sauropods.win
2025-03-24T12:07:19Z
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@futurebird it seems to me that in many (not all) of the ecological situations where big ants would have an evolutionary advantage over small ants, similar advantages could be gained more easily by evolving a larger ant ant colony. If that's correct, it might be that large ants require a rare combination of factors.
(DIR) Post #AsNZ5jlEsfgk9f3HSS by grootinside@troet.cafe
2025-03-24T12:07:43Z
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@futurebird @noodlemaz Time for "Phase 4"
(DIR) Post #AsNZDYIHOnhauIEV9c by Phosphenes@mastodon.social
2025-03-24T12:09:04Z
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@futurebird Here's my big question: Every endoskeleton on Earth descends from the same ancestor, one with a dorsal spine. Why? Does this mean that endoskeletons are *extremely* unlikely in evolution, and if we found alien life almost none of it would have endoskeletons?Or does it mean that our particular type of endoskeleton is the only one that could possibly work?Or does it mean that our endoskeletons are so kick-ass in that niche that any possible competitor doesn't have a chance?🤔
(DIR) Post #AsNZFCMNv3anSYwDiK by llewelly@sauropods.win
2025-03-24T11:16:32Z
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@futurebird 2/4Pterosaurs got most of their launch thrust from their arm muscles, and once airborne, they use (mostly) the same muscles for in-flight thrust. In contrast, a bird gets most of its launch thrust from its huge leg muscles, but as soon as it is in the air, the heavy leg muscles no longer contribute to flight. So a bird needs to carry two sets of muscles, leg muscles for launch and wing muscles for in-flight thrust.
(DIR) Post #AsNZFCvToZfJDPMFPs by llewelly@sauropods.win
2025-03-24T11:16:58Z
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@futurebird 3/4The bird-style take off is a huge disadvantage for being big, and that's probably the major reason pterosaurs were able to get so much bigger than birds. But it's still somewhat incomplete; the pterosaurs of the Triassic and the Jurassic were overall quite similar in size to the largest living birds, and not as big as extinct birds like Argentavis or Pelagornis. The giant pterosaurs don't occur until the late Cretaceous.
(DIR) Post #AsNZFDSnogJuskwrM8 by llewelly@sauropods.win
2025-03-24T11:21:29Z
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@futurebird 4/4crap, I left off the real puzzler: there are apparently 4 species of bats (3 in central America, 1 in Aotearoa/New Zealand) that take off the same way pterosaurs do, but none are especially large. Maybe it's because the 3 central american bats are vampire bats, and the vampire life-style just doesn't benefit from being big. The NZ bat is mainly insectivorous, I think - but I'm not sure.
(DIR) Post #AsNZdmSRMPyEMfUZjk by futurebird@sauropods.win
2025-03-24T12:13:51Z
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@KennyPark It not that it's not a factor to be clear It's just not a hard limit as it's often described. Does that make sense?Also, there was a time when these large insects were only found in a period with hight O2 but that has been changing as more fossils are found complicating the picture. But in terms of pop science it's become a factoid with more weight than it merits IMO. Eg."Large insects are impossible now because they could only survive with higher O2 levels."
(DIR) Post #AsNZnf71We4aTlBcxc by futurebird@sauropods.win
2025-03-24T12:15:40Z
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@noodlemaz The Arthro-Core hip hop album no one asked for ... but everyone NEEDS is one of my back burner projects I keep threatening to start taking seriously. "No one wants to hear a teacher trying to spit bars."This is true... but it's not the kind of thing that has ever stopped me before.
(DIR) Post #AsNZqI3nglLXqxvr4C by sophieschmieg@infosec.exchange
2025-03-24T12:14:30Z
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@futurebird oh and to explain why the "uses legs to lift off" is size limiting: Muscles are heavy. Strong muscles are heavier. Being heavy is not for flying, and muscle weight scales cubically while strength only scales quadratically. You need to have giant muscles in order to power flight, and all three flying vertebrate species have those.In order to start flying, you need to have a certain initial speed, especially as the size of the animal increases. So you need more and more powerful muscles to help you lift off as the size increases. If you use the same already humongous muscles you use for flying for liftoff as well, you save on weight, and can make the animal larger.
(DIR) Post #AsNa9erF9Vuo3oIHjc by crcollins@writing.exchange
2025-03-24T12:19:35Z
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@futurebird 😳 I respect your dedication to and solidarity with ants, really I do, but that would be one of my worst nightmares. 😆 I do have giant ants in one of my books. 🐜 😀
(DIR) Post #AsNaSRwrNDd9WasijQ by jfrench@cupoftea.social
2025-03-24T12:22:59Z
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@futurebird I'm picturing you in your evil lair thinking about plans for world dominion. "I could use some basketball sized ants"
(DIR) Post #AsNaYkxPbzOiDX9BNQ by futurebird@sauropods.win
2025-03-24T12:24:10Z
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@jfrench It's nothing like that at all. (My 'lair' isn't evil. It's very charming with lovely bookshelves and comfortable places to rest and read.)
(DIR) Post #AsNvsy76VLRtql9xFA by ersatzmaus@mastodon.social
2025-03-24T12:15:48Z
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@llewelly @futurebird Bat-launch is gravity assisted, given how they roost, right? So presumably they don't need an overpowered launch system.
(DIR) Post #AsNvszDWOyB1GxAasy by RedRobyn@mastodon.nz
2025-03-24T16:01:00Z
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@ersatzmaus Bats in New Zealand also spend time crawling about on the ground. We have a cool subterranean parasitic plant that's flowers are pollinated by the bats. Unfortunately introducing mammalian predators that hunt by scent has done a number on the bats. And made it harder for these flowers to get poillinated.https://www.doc.govt.nz/nature/native-plants/dactylanthus/ @llewelly @futurebird
(DIR) Post #AsO23nqpbFwqvq67GK by futurebird@sauropods.win
2025-03-24T17:32:18Z
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@Virginicus What is “The Man Who Likes Ants” ? How do I not already know of this?
(DIR) Post #AsOjp4n6jP8H6r8zAG by dfraser@mastodon.sdf.org
2025-03-25T01:41:29Z
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@futurebird @noodlemaz you could partner with teacher/turntablist Kid Koala
(DIR) Post #AsPvNxY8wK7RRLwNLk by bcasiello@floss.social
2025-03-25T15:26:56Z
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@futurebird Sadly, science went a different way, going all-in on developing an ant-sized basketball.
(DIR) Post #AsQk219lwaRzuzptHE by Oaktag@infosec.exchange
2025-03-26T00:54:21Z
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@futurebird