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paleopeter — Gnathosaurus sublatus
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Published: 2016-05-30 12:13:48 +0000 UTC; Views: 1243; Favourites: 41; Downloads: 13
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Description
Gnathosaurus. Species: G sublatus.
Meaning of name: Jaw lizard.
Distribution: Germany.
Time: Late Jurassic.
Classification: Pterosauria, Pterodactyloidea.
Wingspan: 1.7m.
Lifestyle: Filter feeder.
Thanks Keri for the background photo, northern California near Lassen volcanic park.
I have modified the port wing so hopefully it now matches the starboard wing (allowing for perspective) this illustration was done primarily to show the forward pointing pteroid idea.
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Comments: 67
This is awesome, but verry outdated. Round These wingtips, give it a Nice and big and flashy crest and muscle up these Wings! Pterosaurs werent mesozoic bats, but much more birdlike - convergent Evolution. Look at my G. rhamphastinus or C. filisurensis for what i mean!
Again this comment is a help for you to improve, and not a rant my friend ^^!
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I had planned to enlarge the crest on its first upgrade. I am happy with the rest of the illustration and pterosaurs weren't like bats or birds, they were like pterosaurs. The musculature is comparable with a similarly-sized flying fox.
I am interested in hard scientific fact that enabled the wing tips to be rounded not just popular trends in illustrations. Any ideas?
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To your last sentence: actinofibrills
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I was hoping for fossil evidence that Gnathosaurus had rounded wingtips rather than what might have reinforced them. A recent trend in paleo art is to show very curved flight fingers even when the fossil evidence shows them to be relatively straight, the first rule of paleo art is that the illustration must fit the skeleton
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yep, but you simply cant fly with sharp tips, otherwise birds and bats and airplanes wouldve have the same shape. try it out and build a paper wing model. i have done so with both theories, and the rounded one waas the only one to even glide
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I have a load of photos in front of me of bats with pointed wing tips!!!!!! Not to mention the Boeing 767-400ER, 777-300ER, 787, Junkers 188 etc. A recent pterosaur find shows the wingtips swept forwards!
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yep bellubrunnus has these wings, but how so often in nature, there are exeptions: seal-like birds for example:s-media-cache-ak0.pinimg.com/7… img.memecdn.com/possessive-pen… or "grasing" sauropods: fopunkt.com/alexandria/donkolo… bbsimg.ngfiles.com/1/14607000/… not to mention carnivorous ungulates listosaur.com/wp-content/uploa… s-media-cache-ak0.pinimg.com/7…
bat wings look pointy when they arent used in flight, the airflow makes em round: www.youtube.com/watch?v=LxzyAa…
and i am talking about wing tips, not winglets/sharklets
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The number of aircraft and animals with pointed wing tips must run into thousands! There is a very good reason for this. As high aspect ratio wings have to be highly tapered to prevent excessive bending leading to catastrophic failure, similarly on aircraft the outer wing leading edge is drooped to prevent twisting that can also lead to catastrophic failure. Broad wing tips would be appropriate for pterosaurs with low aspect ratio wings but there are very few of those. However if a wing is swept forward this overcomes a lot of the problems of bending and twisting in the outer wing so broader wing tips would be possible and this may be applicable to long- necked pterosaurs to maintain their centre of gravity. Gnathosaurus hasn’t a particularly long neck but has high aspect ratio wings like an albatross, also with pointed wing tips.
As for the exact shape of other soft parts that don’t usually fossilise on every individual species, your guess is as good as mine.
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www.davehone.co.uk/wp-content/…
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www.google.de/search?q=pterosa…
Click on first search result
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Hi guys, Jack here with another instalment from the art corner, but before we start, I have an important note:
DO NOT use the work of David Peters as a basis for your palaeoillustration. Don’t get me wrong, he’s a great guy and a phenomenal artist, but his work is unsupported by pretty much every other study done on Pterosaurs, and is so far removed from scientific consensus that he may as well be talking about flying pancake monsters. Do not be fooled by his lovely illustrations and professional graphic design skills. Anything from his websites The Pterosaur Heresies and Reptile Evolution is to be disregarded if you are looking to produce scientifically accurate Pterosaurs. Sorry David, but your methods are questionable and your conclusions are absurd. That being said, do not send David Peters hate mail. Do not hate on David Peters. If you want to read more about Peters’ work and why not to trust it, Darren Naish of Tetzoo fame explains here.
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Did... did you even read the article or look at the search results? That was Dr David Hone, not Peters. Hone is a reliable source. Please go back and look again.
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I know that. I didn't
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people.eku.edu/ritchisong/Lays… sorry, have I heard you saying albatross' wingtips were pointy? Look at the distal feather.
www.wattflyer.com/forums/attac… one of the only flying pterosaur models without a stabilisator at the end. It has rounded tips.
www.davehone.co.uk>2014/01 need more evidence? If the link doesn't work click on the first search result here, it's a PDF.
More to say? This is fun my friend!
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Gliders don't flap
www .youtube.com/watch?v=wi30w-Mk2yQ
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I gotcha' fam! www.youtube.com/watch?v=wi30w-…
None of the shots let you get a clear view of the wingtips though, which again are curved
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It’s just a film showing flying foxes in flight with pointed wingtips
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Except that flying foxes wings are nothing like that of a pterosaur. Bats have the entire hand dedicated to supporting the membrane, allowing them to change the shape as needed. Pterosaurs had no such luxury. Because the membrane is stretched between just one finger, the wingtip needs to be a consistent shape to keep themselves in the air.
As for the pointed wingtips,
"There are a number of common errors made when reconstructing pterosaur wings. One error is to reconstruct the tip as being very sharp. This was an unlikely configuration, because such sharp tips can be prone to a particular form of stall (which will lead to the animal suddenly doing much more falling than flying). Living birds, for example, have somewhat rounded wing tips, and pterosaurs probably did, as well." (From here -> pterosaur.net/flight.php )
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I agree with you entirely except that at their wingtips, bats have just one finger & in large species the wingtip is usually pointed. How do millions of them manage to fly dally/nightly without suffering tip stalls! That is probably why Mike Habib says that probably pterosaurs didn’t have pointed wingtips instead of defiantly
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... You're joking about bats only having one finger, right? That's the thumb, the other four support the membrane...
Also, no, bats do not have super sharp wingtips. The second digit is shorter than the third, and curves around to almost connect with the third digit, rounding the wing out. Not to mention, again, the fact that bats have four fingers (along with a muscle structure called the plagiopatagiales ) they can use to manipulate the shape of their wings as needed.
Exibit A: upload.wikimedia.org/wikipedia…
Exibit B: c1.staticflickr.com/3/2409/216…
Again, pterosaurs only supported the membrane with ONE finger, and did not have the ability to drastically change the wing shape like bats, so they would need a somewhat consistent shape to make up for it. so the wingtips were rounded, and actinofibrils helped keep the membrane from stretching horizontally.
So in conclusion, no, bats do not have sharply pointed wings, bat and pterosaur wings are NOTHING alike, and you seem to confuse "likely" with "I have a hunch".
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Flying creatures and aircraft have a wide variety of wing tip shapes to suit their particular lifestyle. It would be inane to believe that uniquely pterosaurs evolved a single wing tip planform across the entire family. It would be impossible to match the exact wing tip to every individual species however it’s somewhat easier to work out the shape of the wing planforms because it has to fit the skeleton and comply with the laws of physics. Fighter aircraft with high aspect ratio wings and broad cord at the tips are very rare. There was one, the Fokker Eindecker, that had a similar wing plan to that which is popular to depict Pterosaur wings by some paleo artists. Unfortunately the wings snapped with boring regularity causing them to fall out of the sky so much so that the worlds’ air forces became prejudiced against monoplane fighters so that bi-planes predominated for the next twenty years. However, had the wing been designed more like a modern wind turbine with lots of twist and taper towards the tip and less like an old fashioned windmill sail, they would have been perfectly viable. The same principles apply to a high aspect ratio wings on pterosaur and their violent lifestyles.
No-one mentioned super sharp pointed wing tips just you and we weren’t talking about bats – just large species that by my definition have pointed wing tips as have swifts, terns and cuckoos that apparently can’t fly without suffering tip stalls according to some palaeontologist.
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Yep and you could argue with many insects as well. Bats and insects mostly get their lift by pushing air down and don't use air currents and wingshapes to get up.
can you help me here?
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I really have no idea where the idea that bat wingtips are super sharp is coming from... The tips of all their phalanx are rounded, and the second digit helps to round out the overall shape of the wing, being much shorter and curvier than digit 3 and bending around to almost meet with it... I mean, yes it can appear that the wings are pointy (like in this image ), but when flat the wing is so obviously rounded (And again! Curved third digit tips!). Even insects have rounded wings! Flies , wasps , bees , butterflies , beetles , lacewings , true bugs , earwigs ... all of them have rounded wingtips.
Plus, as a MAJOR difference between bats and pterosaurs, is that bats can flex all four fingers to bend and bow the membranes as needed. A pterosaur probably wouldn't be able to do this , or this , or even this ! When flying , bats are constantly manipulating the shape of the wing for maximum efficiency, something that a pterosaur, with only one thick supporting finger and stiff actinofibrils, would have a much harder time doing.
Gif showing bat, bird, hummingbird, insect, and dragonfly flight cycles
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All these distal phalanges are far more curved than any in the fossil record, can you think of another example were paleoartists are actively encouraged to ignore the fossil record?
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Which fossils are you referring to specifically? Because again, curved wing phalanx have been found. One particular specimen was found with its distal phalanx curved forwards, although this was probably a circumstance of decomposition rotating it before fossilization.
Also, the fossil record for pterosaurs is aweful, absolutely aweful. Most everything is crushed, incomplete, or both.
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I was referring to the photos of distal phalanx in Dave Hones article that show a more modest curve than most illustrations including mine. I have put my views on wing shape in my Deviant Journal Entry.
www.davehone.co.uk/wp-content/…
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thats what happens to me all the time:
rationalwiki.org/w/images/f/f6…
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My thoughts exactly (aside from wanting to slap someone)
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XD! Hold on tho, I never had a conversation with paleopeter like this. Normally he's a great guy and corrects mistakes instantly.
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The laws of physics change with scale, you can’t look at minuscule bats & butterflies to judge the flight characteristics of large pterosaurs. If you look at my drawing you can see the port wingtip is much more pointed than the starboard one & the port leading edge is straight between the 2nd & 3rd digit & curved on the starboard wing. This has more to do with being a crap artist than the laws of physics!
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but gnathosaurus isnt that much of a giant. btw, much bigger recent birdo with rounded wingtips:
cdn.xl.thumbs.canstockphoto.co…
more proof:
www.davehone.co.uk/wp-content/…
even more proof:
depositsmag.files.wordpress.co…
bat and bird both round
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You sent me this link it’s worth reading.
One aspect of the pterosaur wing has, however, been almost entirely overlooked in assessments of their flight capabilities — the shape of the wingtip. This aspect of the wing has important implications for how the wing will function. Different wingtip shapes will affect stall thresholds, vortex shedding efficiency, and gust load alleviation, among other factors (Vogel, 2003; Pennycuick, 2008). That pterosaurs present a variety of different morphological shapes to their wingtips as seen in the different levels of curvature to the distal phalanx, attests to potential differences in flight performance and differing morphological adaptations to optimize their flight apparatus to an ecological role. Here we survey the available information on the variety of shapes for pterosaur wingtips. Using aeronautical theory and comparisons to extant vertebrate fliers, we hypothesize the likely effects of these differing shapes on performance and therefore ecology. Special consideration is given to the unusual pterosaur Bellubrunnus and its anteriorly directed wingtips — a feature apparently unique among volant vertebrates.
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You can’t look at minuscule bats & butterflies to judge the flight characteristics of large pterosaurs because bat wings, insect wings, and pterosaur wings are all drastically different! Scale is not the major factor here, anatomy is! Even if they were all the exact same size, their flight dynamics would be nothing alike. There are some common traits shared between all true flying animals, as true flight requires very specific parameters, but all of these features are accomplished in different ways.
However, one thing they do have in common is curvature to the tips of the wings. Yes, even bats have curvature to the wing tips, see my comment here; comments.deviantart.com/1/6121…
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If a dog were to grow to 5 times its normal size, it would weigh 125 times as much. The weight of an object increases as the cube of the scale factor. Another example? Suppose an ant were to grow 200 times bigger. It would weigh 2003, or 8,000,000 times as much.
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Yes, but you are again missing the point (ha?). As I said earlier, "Even if they were all the exact same size, their flight dynamics would be nothing alike."
Also, I never once said scale wasn't a factor at all, just that it wasn't the major factor
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No, you’re missing the point. If a mouse were the same size as an elephant it’s walking dynamics would change completely i.e. its legs would break if it took a step! Clearly what works at one scale doesn’t work at another, why don’t you stick to similarly sized animals to make your point like for example gnathosaurs, flying foxes and seagulls.
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Yes, again I am aware of that. OK, clearly neither of us really understands what the other is trying to argue, so let me rephrase everything I have been trying to say.
What I have been arguing is that pterosaurs do not have narrow, sharp wings with pointed wingtips, as displayed in this image. It would cause the pterosaur to not be capable of staying in the air. Your argument against this seemed to be that bats could fly with pointed wingtips (Which they actually don't, all of the flight fingers are curved to some degree), and my argument against that was that Pterosaur wings and bat wings do not have similar anatomy nor flight mechanics. I'm NOT saying scaling isn't a factor (as I've stated twice now, thrice counting this). I am saying that it is not as big a factor as the differences in anatomy are. To answer why I didn't list your example above, is because, again, that was not what I was trying to argue.
Another argument against pointed wingtips in pterosaurs is that they have, in fact, found direct evidence of curved wingtips, such as soft tissue finds and wing fingers with curved distal phalanges. That Dr David Hone article posted above gave a more in depth analysis of it, along with some direct evidence/examples.
Again, I AM NOT SAYING SCALING IS NOT A FACTOR! Actually, why is scaling even coming up? Pterosaurs did not have sharp, pointed, crescent shaped wings. There, that's what me and TheDubstepAddict have been trying to say.
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I have modified the port wing so hopefully it now matches the starboard wing. Allowing for perspective, the low viewing angle & the fact that it’s slightly swept back because the animal is diving, it’s now very similar to the illustration, fig 1 in David Hone’s article. My illustration was done primarily to show the forward pointing pteroid idea. I am in full agreement with David Hone but feel some paleoartists have misinterpreted what he is saying. When he talks about rounded wingtips he’s referring to the curvature of phalanges 3 & 4, in other words the outboard leading edge not the absolute tip. He says the trailing edge is straight or concave but some paleoartists draw very rounded wingtips with convex trailing edges producing a deep cord wingtip on a high aspect ratio wing! My other point is that pterosaurs would have had a wide variety of wingtip shapes & his article confirms this. Sharply pointed wingtips shouldn’t appear in the fossil record as they are prone to tip stalls but confusingly some Rhamphorhynchus fossils do show pointed wingtips. However he points out that the flight finger is probably made of highly pliant bone so that under tension the whole flight finger could bend to the point that the tip of the distal phalange is pointing backwards. He also talks about vertebrate flyers so clearly he doesn’t want insects to be brought into the argument either (that is how scaling came up). Thank you for your comments on this drawing I hadn’t realised how flawed it was & probably still is!
www.davehone.co.uk/wp-content/…
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what has this to do with gnathosaurus? the animal most resembling it today has rounded wingtips: s-media-cache-ak0.pinimg.com/2…
same environment, same mass, same airsacs, same diet, kinda the same physics
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Take a look at the Rhamphorhynchus fossils in Wikipedia same time, same place, same species, not opinions, fossils!
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