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Twarda8 — At dusk: Daohugou biota
#animals #fern #forest #night #nightforest #palaeoart #paleoart #pterosaur #pterosaurs #jeholopterus #volaticotherium #daohugou #pangerpeton #thesummonengh2018 #summonengh
Published: 2018-10-31 17:37:38 +0000 UTC; Views: 4075; Favourites: 304; Downloads: 23
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Description
Formacja Tiaojishan, konkretniej biota z Daohugou (sporo osób się zgadza z zaliczeniem tejże do tej formacji).Na potrzeby uzyskania interesującego światłocienia, pora dnia została deko przyciemniona. Oraz, ze względu na obecny słaby skill w renderowaniu wegetacji, rośliny są raczej uproszczone...
Pierwszy plan: Muscites sp. niesprecyzowany Equisetites/Equistetum, Sphenobaiera sp.. Nasiona Pityospermum, liście Pityocladus. Główna paproć ogółem bazuje na Cladophlebis.
Pangerpeton sinensis - gruba salamandra - na dole. W górze: Jeholopterus, lecący wśród jętek. Rośliny w tle obejmują szpilkowe drzewo, na którym siedzi Volaticotherium, Ginkgo sp. i benetyt Anomozamites sp.
Pajęczyna należy do mongolarachnida.
Ilustracja została zrobiona w taki sposób, aby, wedle uznania, można było ją podzielić na 2 osobne obrazki.
(Jeżeli praca wygląda za ciemno, mogę dostosować jasność i kontrast; na moim kompie wygląda ok, ale z ciemnymi ilustracjami to nigdy nie wiadomo).
Zainspirowane i zrobione dla the SummonEngh.
Related content
Comments: 25
Needs more wings: ichthyoconodon.wordpress.com/2…
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But this is a pterosaur, not a mammal.
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You have Volaticotherium in the background?
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Ah, I missed that little guy the first time.
In any case, there isn't really enough evidence to conclude that Volaticotherium was a true flyer. It's a fringe theory that seems to be pushed by only one person, and he's making himself out to be a real David Peters in this situation.
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Also, "fringe":
Sigogneau-Russell, Denise (1995). “Two possibly aquatic triconodont mammals from the Early Cretaceous of Morocco” (PDF). Acta Palaeontologica Polonica. 40 (2): 149–162.
Gaetano, L.C.; Rougier, G.W. (2011). “New materials of Argentoconodon fariasorum (Mammaliaformes, Triconodontidae) from the Jurassic of Argentina and its bearing on triconodont phylogeny”. Journal of Vertebrate Paleontology. 31 (4): 829–843. doi :10.1080/02724634.2011.589877 .
Alexander Averianov; Thomas Martin; Alexey Lopatin; Pavel Skutschas; Rico Schellhorn; Petr Kolosov; Dmitry Vitenko (2018). "A high-latitude fauna of mid-Mesozoic mammals from Yakutia, Russia". PLoS ONE. 13 (7): e0199983. doi:10.1371/journal.pone.0199983. PMID 30044817 .
Qing-Jin Meng; David M. Grossnickle; Di Liu; Yu-Guang Zhang; April I. Neander; Qiang Ji; Zhe-Xi Luo (2017). "New gliding mammaliaforms from the Jurassic". Nature. in press. doi:10.1038/nature23476.
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Aquatic does not mean flying. Gliding is not the same as true flight, which is what he was proposing. And none of these say anything about Volaticotherium being a flyer akin to bats.
This is not to discredit the validity of any of those studies, but they simply aren't supporting your point.
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The point is that those studies show that A) there was no post-mortem aquatic transportation (leaving either aquatic or aerial dispersals as the only options), that (per Meng et al) only herbivorous mammals are gliders, and C) that the distribution of volaticotherines is noted as "interesting".
All this, to mean, means powered flight is a very likely option.
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I would hesitate to say it's "very likely," since there really isn't any direct evidence pointing to the animals having powered flight. These animals come from a family of gliders (not to mention that the small flying carnivore niche was very much filled at the time these mammals were alive).
Also, saying that mammalian gliders can only be herbivorous is like saying reptiles can only be exothermic, which we know via dinosaurs and their relatives to not be the case. Comparing long-dead animals that lived in an entirely different ecosystem from today's Earth to extant species, while not pointless, creates a really narrow point of view when trying to figure out what these animals were like in life. Sure, all of today's mammalian gliders are herbivorous, but that definitely doesn't mean that that has always been the case. Carnivorous and insectivorous gliders also exist in other clades, such as theropod dinosaurs with Microraptor, so it's entirely possible mammals would have an equivalent in areas and times where those creatures would be absent.
In all, we can't say it's impossible that these animals flew. However, saying it's likely is a pretty big conclusion to leap to, especially with so little fossil evidence.
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The only reason they're considered gliders is that the forelimbs are not well preserved.
As noted by Meng et al 2017 and Jackson 2012, gliding mammas are predominantly herbivorous. Gliding is quite energy expesive as it demands climbing around repeteadly; it is mostly used to cover large distances in search of stationary food stuffs. The ecology of the Mesozoic might not match entirely with today's, but in this aspect it seems it did; gliding haramiyidans even resemble colugos and flying squirrels in terms of dietary prefferences.
Also, there are today there are Accipitriformes, Falconiformes, owls, several different lineages of predatory bats, frogmouths and skuas, and earlier in the Cenozoic even more predatory bird and bat clades. Competition isn't much of an issue, especially if Mesozoic habitats were richer in biodiversity.
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Isn't that a lot of the basis of why you're saying their flyers?
And yes, gliding is energetically expensive, but one could argue flying is moreso, especially the constant flapping flight bats use (which is what you compare Volaticotherium to, yes?). Flight is generally used to catch moving prey, true, but animals will only develop flight if they absolutely need to. Carnivorous gliders have existed, and it's most definitely possible that mammals had their own version of them.
There has also been a trend shown that gliding animals are almost always specialized in just gliding, as is stated in a paper by K.L. Bishop. Most gliding mammals have a styliform bone that isn't present in flying mammals, and is a direct result of needing to be able to climb efficiently while also having solid support for gliding wings, as well as a slew of other morphological humps to overcome if they were to evolve flapping flight. Volaticotherium's hands are poorly preserved, yes, but the absence of evidence for these gliding features is not confirmation of the presence of flying ones. Its relatives are gliders, so it's very likely Volaticotherium and Ichthyoconodon were, as well.
And that's fair, though it's still something to consider when looking at incomplete fossils.
Source for the second point:
Bishop, Kirstin L. “THE EVOLUTION OF FLIGHT IN BATS: NARROWING THE FIELD OF PLAUSIBLE HYPOTHESES.” Quarterly Review of Biology, vol. 83, issue 2, 2008, pp. 153-169, web.b.ebscohost.com.cod.idm.oc… .
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There are no known carnivorous gliding mammals; the closest are sugar gliders, but they stillrely on a primarily herbivorous diet. Bats became aerial through fluttering, not gliding. Pterosaurs have no transitional fossils, but early species have adaptations for hopping, suggestng that they indeed evolved from terrestrial Scleromochlus-like species.
In general, early representatives of flying tetrapod groups tend to be carnivorous, as ealy bats and pterosaurs demonstrate. This fits perfectly in regards to the obligate carnivore diet of volaticotheres.
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No known carnivorous gliding mammals doesn't mean none exist. In fact, it's looking likely that the Volaticotheres were carnivorous gliders. And right, most flying animal groups seem to have come from terrestrial creatures that flapped, which makes a flyer coming from arboreal gliders even less likely.
The therapod dinosaur gliders were all carnivorous, as well, so it's very within the realm of possibility that mammals had carnivorous gliders, as well (especially considering that seemed to be a very successful way of life in the second half of the Mesozoic, looking at how many species we have from the therapods that adopted it).
My entire point with this is that incomplete fossil evidence does not demonstrate that these animals were true flyers. We have no direct evidence that they were capable of flight, since the hands of Volaticotherium are incomplete, and its relatives glided. And if there is that much uncertainty, we definitely can't say it's likely that they were flying animals.
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The only oter evidence of "gliding" in volaticotheres is in Argentoconodon, which demonstrates a femur similar to Volaticotherium's. For all we know it is another evidence of powered flight, especially since such a specialised femur that restricts terrestrial locomotion would be disadvantageous for an animal that needs to climb around.
I'm discussing in my to-be-published Jugulator paper the inner root structure of these mammals, which is kind of akin to that of bats.
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Le sigh:
www.amazon.com/Possible-flight…
Going to get a paper published soon, so you might want to revist that David Peters connection.
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Where is this paper being published?
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Clever, I see you.
Do link me your paper when it gets published, I'd love to read it.
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Thank you, I will. In the meantime, my ichthyoconodon.wordpress.com has several core arguments.
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I'll look into those, thanks.
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Not gonna lie, I though this was a real photo😳
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