enter image description here

art by ticklemecthulhu

In my world of arthropod-like creatures (in that most of the creatures have an exoskeleton rather than an endoskeleton), I wished for a group of my aliens to convergely evolve into pterosaur-like creatures, resulting in a previous question about this, though then I was more focused on whether it was possible.

Overall, the goal is for an animal with a roughly pterosaur-like appearance, including wings made of a limb with an elongated finger-like extension and a flexible living membrane made of muscle, blood vessels and support fibers which allow for changes in the membranous surface. The creature has bird-like circulatory and respiratory systems. The image above somewhat illustrates what I originally thought would be necessary: the presence of a "groove" alongside exoskeleton plates allowing for the passage of blood vessels meant to keep the membrane alive as well as to allow for a connection point for the membrane itself.

My doubt however came while I researched for how this should look like by looking at the joints of arthropods, when I came into contact with the strange world of fly mouthparts (particularly hoverflies), where I found out some of them have mouthparts seemingly covered up by a flexible, living membrane that apparently attached directly to the rigid parts, which left me puzzled about how my approach at wings should look like. Warning: Nightmare Fuel.

enter image description here enter image description here

So summing up: what should an arthropod-like creature's exoskeleton look like from an anatomical perspective to accommodate for a living membrane? Given what we know about arthropods on earth, would this "soft" line along the animal's body and limbs be truly necessary for the attachment of the membrane and passage of nutrients or would it be possible to attach it directly to the hardened parts with only certain openings near the joints being enough for the passage of nutrients? I haven't been able to find further details on any similar kind of membrane in arthropods other than this case, and even then I couldn't find much about it.

Their overall body shape and wing membrane attachment is similar to that of an azhdarchid pterosaur

enter image description here

  • $\begingroup$ have you looked at terrestrial beetles - they probably present an excellent starting point. Also see the initial inflation and hardening of wings once butterflies emerge from their cocoon. $\endgroup$
    – Rory Alsop
    Commented Oct 1, 2022 at 23:11
  • 1
    $\begingroup$ there are insects with folding wings. earwigs and beetles, $\endgroup$
    – John
    Commented Oct 2, 2022 at 1:56
  • $\begingroup$ @RoryAlsop I did look at them as well as other insects known to be good fliers, but overall it seems like the insect wings as we know them aren't exactly efficient for what I need, still being rather fragile (though not nearly as much as you'd expect) and less dynamic as living membranous wings, as well as having a lower ability to carry the creature. $\endgroup$ Commented Oct 2, 2022 at 18:42
  • 1
    $\begingroup$ That's okay. I didn't plan on getting any sleep tonight anyway. I've slapped a warning on those images for the sake of the rest of mankind. $\endgroup$
    – Daron
    Commented Nov 21, 2022 at 20:45
  • $\begingroup$ @Daron thank you very much, I know some people aren't as into insects, but I didn't know how to hide images like that. $\endgroup$ Commented Nov 21, 2022 at 21:39

2 Answers 2


According to the Wikipedia article on "insect wings", the wings themselves are outgrowths of the exoskeleton, and would reasonably be able to connect to a stronger limb-like structure, perhaps with folds to accommodate the movement of the wing. However, since your bug-creature isn't strictly an arthropod, it may be quite reasonable to cover the wing appendages entirely with a thin membrane in order to secure the flexible flight membrane to the hard limb. The membrane could be thin and transparent, supplied by pinholes in the exoskeleton, similar to the spiracles that let air through the chitin of a normal insect. Having it wrapped around the limb would avoid having to attach it directly to the hard exoskeleton.


Here is why it wouldn't work on earth, and how it might work on your planet.

Disclaimer: I have no way to prove my answer for certain, as I am not capable of creating life.

Compared to other creatures, this will be horriblly inefficient. This only has to do with the current existing creatures, and your own creature developed along with it's own set of threats.

Arthropods do not have a closed circulatory system. Most are too small for it to matter, consider the fact that every cell of your body is within 2 mm of a blood vessel, and it makes sense how smaller creatures don't need it. Your creature must have normal blood vessels in it's wings, or perhaps separate hearts.

Square Cube law (I know it sucks.) means that it will be hard for you to achieve flight. Your planet might have a denser atmosphere, preferably with extra oxygen to achieve a proper size.

Is it possible for it to be attached? Of course it is. It is merely an extra two limbs with membranes.

  • 1
    $\begingroup$ arthropods do have blood vessels they just lack a completely closed circulatory system. $\endgroup$
    – John
    Commented Mar 8 at 23:54

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .