How pterosaurs flew

Matthew Cobb called this video to my attention, and I thought it was worth putting up.  Anhanguera is a genus of flying reptile that contains three described species. They were about 1.2 meters tall (four feet) with a 4.5-meter (15-foot) wingspan, and were heavy—weighing about 23 kg (50 pounds). They lived roughly 120 million years ago. Although Wikipedia describes them as fish-eaters, the New Dinosaurs site says this:

This is one flying reptile that you may not recognize from Anhanguera pictures. That’s because this pterosaur was discovered relatively recently – as compared to other flying reptiles – and doesn’t get the media attention that pterodactyls do. Which is quite a shame because this was one remarkable creature.

. . .  its wingspan was about 3 times larger than a Crowned Eagle and its weight was about 12 times heavier than a Red-tailed Hawk. It had crests not only on top of its beak but also on the bottom.

One of the most interesting facts about Anhanguera is that it had relatively weak legs. Which means that it probably spent the majority of its time flying. If it did spend any time whatsoever on the ground, then it most likely walked with a very unusual gait and probably was a little wobbly.

Most paleontologists believe that this pterosaur used its beak to scoop up fish, but it is also possible that it hunted for carrion from dead animals that it discovered on land as well. It may have also eaten a variety of different insects as well. Which means that it may have had one of the most diverse diets of any flying reptiles of its time.

We have much of the skeleton, and reconstructions vary in external appearance, because of course we don’t have feathers. Here are two:

Here are some bones used in the reconstruction of a specimen’s skeleton (species not clear), and below that is the holotype (original specimen) skull from  A. blittersdorffi:

Skull: (lower jaw missing); note the crest near the tip of the beak:

 

The cool part is the video below, which was made by London’s Natural History Museum. It doesn’t name the narrator, but it sure sounds like David Attenborough to me. The single-leap takeoff is amazing:

This animal is Anhanguera, one of the flying reptiles that lived alongside the dinosaurs. Pterosaurs lived alongside dinosaurs, but they formed a group of their own. Pterosaurs were evolutionary cousins of dinosaurs, and shared many features of their skeletons with them. But unlike their land-dwelling cousins, they took to the air. For the first time ever, we can watch how it might have flown. This animation was made for Hold the World, a virtual reality experience set behind-the-scenes at the Museum.

Notice that what supports the wing membrane is a single digit: the elongated fourth digit, shown below. The other digits were present, as they are in the reconstruction above, but are tiny. They may have helped the creature clamber about on the ground, as shown above, or they may have been relatively useless vestiges of ancestral fingers.

47 Comments

  1. mikeyc
    Posted June 23, 2018 at 11:54 am | Permalink

    “We have much of the skeleton, and reconstructions vary in external appearance, because of course we don’t have feathers.”

    I didn’t know they had feathers. I know some pterosaurs had a fur like covering -called pycnofibers- but I didn’t know about feathers.

    • nicky
      Posted June 23, 2018 at 12:21 pm | Permalink

      They did not have feathers, but were probably hairy (some fossils show hair, but we don’t know if all pterosaurs were hairy) you’re right there. It should be noted they were the first tetrapods having active flight. I think the earliest are from the early Triassic, well before birds.
      Their wings were different from birds or bats, they had these ‘tubule-like reinforcements’ in their wing membranes, as shown in the last picture.

  2. Randall Schenck
    Posted June 23, 2018 at 11:55 am | Permalink

    Would have been an amazing site to see. No real feathers and no tail structure. All the maneuver must be done by the wings, no rudder. You probably don’t want to get bombed by one of these.

    • nicky
      Posted June 23, 2018 at 12:26 pm | Permalink

      The earlier pterosaurs, the Rhamphorhynchids, had long tails with a vane. That would have given a more stable flight, but less arial acrobatics.

      • Randall Schenck
        Posted June 23, 2018 at 12:54 pm | Permalink

        Would have been nice to be there 120 million years ago to see them flying. But then, we probably would have looked like snacks.

        • nicky
          Posted June 23, 2018 at 1:17 pm | Permalink

          I fully agree it would have been a sight, but I doubt we would have been considered snacks: way too big.

          • nicky
            Posted June 23, 2018 at 1:39 pm | Permalink

            Well, except for the giants like Quetzalcoatlus, Arambourgiana or Hatzegopteryx.

            • Mike
              Posted June 24, 2018 at 7:00 am | Permalink

              Or the odd Carnosaur or some other land dwelling giant Carnivore

          • Posted June 23, 2018 at 3:02 pm | Permalink

            There were, however, plenty of terrestrial predators that would make a snack of us while we are busy pterosaur-watching (or maybe it should be pterosauring).

  3. Michael Fisher
    Posted June 23, 2018 at 11:55 am | Permalink

    HOLD THE WORLD

    commissioned by Sky VR Studio, will transport you behind the scenes of the [Natural History] Museum and take you on a guided tour of collection highlights with the world’s foremost natural history broadcaster, Sir David Attenborough.

    Users will be instantly transported to areas of the Museum that are usually closed to the public, in the groundbreaking interactive experience that is launching this spring.

    Using a headset and controller, participants will be able to peek inside the Conservation Centre, Cryptogamic Herbarium and Earth Sciences Library, and handle rare and priceless objects.

    Attenborough, who was digitally recreated as a lifelike 3D hologram for the experience, will impart his expert knowledge about a series of specimens, including a blue whale, Stegosaurus, trilobite, dragonfly, butterfly and pterosaur.

    A 3D hologram of Sir David was created using volumetric capture by Microsoft in their Seattle studios

    Participants will be able to virtually pick up, hold, enlarge and bring to life these specimens in a way that until now had never been possible.

    Sir David Attenborough says, ‘Sharing my passion for the natural world is something which I have done for many years through different technologies, from the days of black-and-white TV to colour, HD, 3D, 4K and now virtual reality

    • Mark Sturtevant
      Posted June 23, 2018 at 12:49 pm | Permalink

      3D reconstructions of Attenborough somehow seems funny to me. But in any case, he is a world treasure and in the distant future we will need to bring him back to life with this technology so that audiences can see how he moved and what he sounded like. 🙂

  4. Mark R.
    Posted June 23, 2018 at 11:56 am | Permalink

    The detective work that leads to these reconstructions by paleontologists is remarkable…not to mention the computer imaging.

  5. Michael Fisher
    Posted June 23, 2018 at 12:16 pm | Permalink

    New Dinosaurs site quoted in OP:

    it had relatively weak legs. Which means that it probably spent the majority of its time flying. If it did spend any time whatsoever on the ground, then it most likely walked with a very unusual gait and probably was a little wobbly.

    Most palaeontologists believe that this pterosaur used its beak to scoop up fish, but it is also possible that it hunted for carrion from dead animals that it discovered on land as well. It may have also eaten a variety of different insects as well. Which means that it may have had one of the most diverse diets of any flying reptiles of its time.

    We know it lived in a large, warm, shallow sea environment. It reminds me of an albatross or frigatebird & I think the “most diverse diets of flying reptiles of its time” conclusion is a bit odd. Based on what info are they making the claim?

    • Christopher
      Posted June 23, 2018 at 12:34 pm | Permalink

      Statements like that tend to bug me as well. I’m not a paleontologist so I don’t know how they decide these things, however, the history of paleontology is littered with such claims. The Walking with Dinosaurs was crammed with statements like that.
      They did say it “MAY have had”, but then, it MAY NOT have had, so what’s the point of making a statement like that, a sort of weasely surity, rather than laying out the evidence, or in absence of such, just saying that we don’t know. Perhaps someone on Tw*tter could ask Darren Naish or Mark Witton for clarification.

    • Mark Sturtevant
      Posted June 23, 2018 at 12:52 pm | Permalink

      I was going to comment on that too. Teeth like that are used for snagging fish and not for carrion. Except for dead fish.
      Well, gut contents will settle this one.

  6. nicky
    Posted June 23, 2018 at 12:31 pm | Permalink

    Those crests on their beaks make us think of a ‘skimmer’-like way to catch prey. Or it might have to do with sexual selection. In the latter case one would expect some male-female difference though.

    • Michael Fisher
      Posted June 23, 2018 at 1:25 pm | Permalink

      The male/female crest difference exists in at least some species – see below

  7. CAS
    Posted June 23, 2018 at 12:31 pm | Permalink

    Miss these flying giants.

  8. Posted June 23, 2018 at 12:32 pm | Permalink

    Here’s a link to an interesting blog post on pterosaur flight.

    http://markwitton-com.blogspot.com/2018/05/why-we-think-giant-pterosaurs-could-fly.html

    • mikeyc
      Posted June 23, 2018 at 12:51 pm | Permalink

      Very nice! Thanks for the link. Quad-launch!

  9. Jon Gallant
    Posted June 23, 2018 at 12:34 pm | Permalink

    Thanks for this. Fascinating. The inflated rubber pterandon hanging on my living room wall would have flown over to join me in watching the video, except that it is extinct.

  10. Posted June 23, 2018 at 12:51 pm | Permalink

    I’m a big fan of the pterosaurs. I want to recommend a really beautiful book, “Pterosaurs: Natural History, Evolution, Anatomy”, by Mark P. Witton. He’s a paleontologist AND an excellent illustrator. The book is full of science and beautiful illustrations. One takeaway from the book is that there were many species that probably occupied many ecological niches. I see it can be had new in hardcover for only $21, even less used. It is a coffee table quality book.

    Here’s one of his illustrations:
    https://goo.gl/images/tqKiBY

    • Mark Sturtevant
      Posted June 23, 2018 at 12:55 pm | Permalink

      The remarkable head and beak crests of these creatures always make me wonder what they were for. I wonder if they were used for rudders or counterbalance, since they seemed to be otherwise animals based on a ‘flying wing’ design, which is inherently very unstable.

      • Michael Fisher
        Posted June 23, 2018 at 1:21 pm | Permalink

        It is tempting to compare bird control with airplane control, but birds are able to fly very well in unstable configurations – they have the micro-controls that makes this possible – something only recently possible in our airplanes. The crest serves as display in at least some species, though nature loves multi-functional design:

        Chris Bennett, a palaeontologist, dismissed both theories while showing me a Pteranodon fossil in the museum basement at the University of Kansas. The animal looked comically out of proportion, with a stretched-out skull that dwarfed its torso and hind limbs. To explain its huge head, Bennett invoked the same reason that teenage boys swagger: To establish rank among the guys and to impress the girls.

        While studying Pteranodon fossils, Bennett concluded that the adult specimens fell into two categories. One group had big crests and small pelvises. The other had small crests and big pelvises. The latter were females, Bennett reasoned, because the large pelvises helped in laying eggs. The big crests belonged to the males. “My explanation for this is that the crest was a display device like the horns and antlers of mammals or the fancy feathers of birds,” Bennett said. “I believe that Pteranodon was polygynous, that one male would mate with many females and only the dominant males would be mating with the females”

        SOURCE

        • Mark Sturtevant
          Posted June 23, 2018 at 3:59 pm | Permalink

          That is good! One lesson that I don’t mind learning over and over again is that animals seem to be more capable of doing stuff than what is predicted by human modelers. The quintessential example of course is the prediction that bees should not be able to fly.

    • Posted June 23, 2018 at 2:15 pm | Permalink

      An excellent book!

      /@

    • ThyroidPlanet
      Posted June 23, 2018 at 2:41 pm | Permalink

      Library’s got it – thanks!

      And three cheers for libraries!

  11. Posted June 23, 2018 at 2:17 pm | Permalink

    Hi, Jerry. Do you know the paleoartists who painted those pictures?

    /@

  12. ThyroidPlanet
    Posted June 23, 2018 at 2:40 pm | Permalink

    This is a nice write up!

    I have wondered… so in the way everyone says dinosaurs became birds, did pterosaurs become lizards?

    • Posted June 23, 2018 at 3:05 pm | Permalink

      No …

      Lizards (and snakes) split off earlier from all archosaurs (crocodilians, pterosaurs, & dinosaurs).

      /@

  13. Posted June 23, 2018 at 4:21 pm | Permalink

    I took this photo of a pterosaur on display at Miami Zoo a little over three years ago.

    Anyone who knows anything about aeronautics will instantly realize that this animal could not possibly fly.

    • Posted June 23, 2018 at 4:44 pm | Permalink

      Here’s another shot from farther away that shows the plaque at the bottom with information about the species.

      A winged aircraft, and presumably any winged animal, has to have a center of gravity near the center of lift, which means somewhere on the wing. It’s generally somewhere forward of the wing’s mid-point but always behind the leading edge.

  14. nicky
    Posted June 23, 2018 at 10:26 pm | Permalink

    Wings, meters long, and not able to fly? I’d tend to suspect that there is rather something wrong with basic aeronautics.
    See also Mark’s remark about bees at 8.

    • infiniteimprobabilit
      Posted June 24, 2018 at 1:38 am | Permalink

      If that’s in reply to Dr I Needtob Athe, I have to say I agree with him. The animal *as reconstructed by the zoo* has to be wrong. Compare its wing shape and positioning with the topmost illustration on this page.

      Assuming the reconstruction has the correct length of neck and its beak is as heavy as it looks, I’d say its wing bones had to be spread out more – like the ones in the NHM video – thus bringing the centre of lift further forward. Whoever did the reconstruction at the Miami Zoo probably had flying squirrels in mind – but look how far forward their front limbs are.

      cr

      • Diane G
        Posted June 24, 2018 at 2:07 am | Permalink

        “…and its beak is as heavy as it looks…”

        Something that leads many to think that toucans shouldn’t be able to fly, too.

        • Diane G
          Posted June 24, 2018 at 2:08 am | Permalink

          & sub

        • nicky
          Posted June 24, 2018 at 10:34 am | Permalink

          Yes, good point, And bees can’t fly either, according to aeronautics as mentioned by Mark Sturtevant at 8.
          I ‘m sorry I could not access the pictures Dr I need to bAthe, linked to, -they might be wrong- but meters long, aerodynamic wings are indicative of flight. They definitely were not used to cut the grass (which did not exist yet anyway).

      • Michael Fisher
        Posted June 24, 2018 at 3:05 am | Permalink

        It’s all dodgy stuff. A holotype for Quetzalcoatlus northropi doesn’t exist – only one adult skeleton of Quetzalcoatlus has ever been discovered & that consists of fragments of just one wing! “We” know [from Witton/Habib – see below] that some, or all, of the very large pterosaurs could fly, but that pic of a model of Q, linked to by Dr. I. Needtob Athe is perhaps rather imaginative [as infinite above says].

        I got the above info from this npr article from November 2010 describing the work of Habib & Witton who used computer modelling & plugged in factors like wingspan, weight & aerodynamics. According to them Qcould:

        “fly up to 80 miles an hour for 7 to 10 days at altitudes of 15,000 feet. The maximum range, Habib says, was probably between 8,000 and 12,000 miles”

        BUT…

        We have the LINK supplied by Sedgequeen to more recent material from Witton [I urge people to read!] & he makes a very convincing case indeed.

        BUT…

        What about Dr. I. Needtob Athe’s point about centre of gravity specifically for Q? I would say – wouldn’t it be nice if we had an adult skeleton of Q? Perhaps we have the neck length wrong – the vertebrae not growing as long as we suppose and/or wouldn’t it be nice to have some ribs to estimate torso weight?

        My overall feeling is – how well would we be able to gauge the remarkable characteristics of a swift from part of one wing? Anthropologists, like all scientists it seems, are under pressure to churn out the papers. More fieldwork might be the answer!

      • nicky
        Posted June 24, 2018 at 10:17 am | Permalink

        I could not access the pictures DrIneedtobath posted, but it is either one of 2: the pictures are wrong, or the basic aeronautics are wrong. (Mark’s bee remarks under 8, leads us to think tha latter is quite probable) These pterosaurs did fly, there can hardly be any doubt about that.

      • Posted June 24, 2018 at 10:47 am | Permalink

        “The animal *as reconstructed by the zoo* has to be wrong.”

        I believe that and several other dinosaurs were part of a traveling exhibit that was on display at Miami Zoo from Jan. 24 until May 10 of 2015, so it wasn’t the zoo’s fault. 😉

  15. Morsgotha
    Posted June 24, 2018 at 5:57 am | Permalink

    Just adding a comment in as PCC(E) wonders why not so many comments on his science posts. I do read them sir, I just feel unqualified to comment!


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