Monday, 1 November 2021

Are there dragons on Furaha?

 No, of course not!

Dragons are mythological beings, usually shown as very large scaly reptilian animals with four legs and two batlike wings. Did I mention that they breath fire and that some of them can talk? Of course, there are no such creatures on Furaha, but the human citizens of the planet did not shed their myths when they relocated to another planet, so they brought stories and depictions of dragons with them.

The citizen-scientists duly observed, with great interest, that six-legged beasties had taken to the skies and now had evolved into excellent flyers (‘not long’ should be taken literally: the animals flew around the spacers’ heads the moment they stepped out of their ship). Closer inspection revealed that some of these animals had four wings (and two legs) while others had two wings (with four legs). 

Click to enlarge; copyright Gert van Dijk

Later speculation suggested that both groups, the Quadrialata and the Dialata, had separately evolved from animals using membranes between all six legs to glide down from one tree to another. In one group, the middle pair of limbs had increased quickly in size, whereas the front and middle pair of limbs turned into wings in the other group.

While the scientists started studying mechanisms of lift and anatomical adaptations to flight, classifying everything meticulously, the general public took one glance at the four-legged two-winged avians and shouted ‘They’re DRAGONS!’. Now, scientists generally dislike lay people interfering with their subject matter, and protested that the animals were not dragons at all; they were ‘Dialata’, not dragons, and dragons did not exist anyway.

Of course, this resistance was futile, and the concept of ‘Furahan dragons’ was quickly assimilated by everyone except the scientists in question.                 

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So much for the ‘in universe’ version of dragon lore. What happened is that the ‘Great Hexapod Revolution’ is in full swing, and I am now working on flying hexapods. The good news, by the way, is that I now think that I only need to do about four of five new paintings to finish The Book. I am aiming at some 140 pages, so you will get your money’s worth (if I find a publisher, that is).  

The unfeathered bird by Katrina van Grouw

 

I am working on my first painting of a Dialate flyer. I took the revamped general hexapod body scheme and thought about how it would need to be modified to become a successful flyer (also see here). Beautiful examples of such anatomical adaptations can be found in the book ‘The unfeathered bird’ by Katrina van Grouw. The image above was taken from that book, and shows the extent of anatomical  modifications.

The elongated hexapod body would have to go, to keep the mass centred. That meant that the frame of the animal had to be shortened, with the hind and front legs bending down towards the middle of the animal. These walking legs also became small and slender, whereas the wings, the middle limbs, increased in mass. The wing skeleton resembles the ‘bat mode’ more than the ‘bird model’, as it has  intact ‘finger’ bones. Of course the toe/finger pattern is not as nicely radial as in Earth’s vertebrates, but flows a Devonian branching pattern instead. The wings themselves are only partly membranous, so they do not really resemble bat wings that much.  

 

Click to enlarge; copyright Gert van Dijk

Here is a simple model done with Zbrush. People can achieve amazing results with Zbrush, but I am definitely not one of them (and I am not alone in disliking its complex convoluted completely counter-intuitive interface). The body and walking legs are sculpted and show the by now general zag-zig-zag basic hexapod pattern.  The wings are only shown as a sort of scaffolding (‘Zspheres’). Their Devonian branching is obvious. 

Click to enlarge; copyright Gert van Dijk


Here I have given up on making the sculpt follow the scaffolding, so you only see the scaffolding. The scaffolding is NOT the animal’s skeleton, but just a shape placeholder (the bumps on the body just indicate its size). Notice how the walking legs are tucked away against the body. 

Click to enlarge; copyright Gert van Dijk

And here is the same animal (Draco umbraferens), clinging on to a reed or stem, looking down to see if here is anything in the water it might eat. It unfolded one wing to provide shade, either to lure animals to the shade, to see better underwater, or both.

I liked that pose, so I developed it further. I am not going to show the painting, which isn’t finished yet anyway, but thought you might wish to see part of it. The Draco will be sitting on a reed in a marsh in bright sunshine. I used Vue Infinite as I often do to compose the scene to help with lighting and perspective, but only roughly. 

Click to enlarge; copyright Gert van Dijk

The scene provided a challenge, as it deals with reflections, transparency and shadows. The image above shows a detail of the future painting: a background plant. Panel A shows the shadow the plant casts on the marsh bottom; B shows the part of the plant that is underwater; C shows the shadow the above-water parts of the plant casts on the water surface; D shows the part of the plant that is above water, and E shows the reflections of that part on the water surface. Finally, panel F shown all parts together, with transparency adjusted to provide a realistic image; or I hope so anyway. The Draco and the reed it sits on will be constructed similarly.


That's it; the next post will probably be about hexapod gaits, and will include the sounds of some gaits, including a hexapodal gallop…      







10 comments:

Keavan said...

Always glad to see another blog post!

With the branching pattern, their wings remind me as much of insect wings as bat wings.

Keavan said...

Also, on further reflection, Dialatan wings really do look strikingly alien, and perhaps a little ungainly. In birds and pterosaurs, the wing digits closely hug the leading edge of the wing, and curve uniformly towards the trailing edge. In flying fish and bats, the digits radiate from a point at the leading edge, and also smoothly curve towards the trailing edge. In contrast, in the Dialatan wing, where the first finger branches from the second, and the fourth branches from the third, there is a noticeable bend towards the leading edge.

Abbydon said...

It's good to hear that the book is almost finished. I guess it's not quite going to be ready for Christmas though unless you just self publish it as a PDF somewhere.

As for the dragons, err, I mean dialata, are there any that use all six limbs to control the wing surface?

Keenir said...

those "simple models" you've made, definately are amazing to me. (and not just because I wouldn't be able to get a third of that accomplished). kudos to you!

to Abbydon - so, sort of like the Furaha version of a Flying Lemur?

(and maybe give The Book a PDF brochure/sample, to get interest? or a Kickstarter?)

-Anthony Docimo.

Sigmund Nastrazzurro said...

Keavan: The wings of birds, bats and pterosaurs differ in many respects. As you said, in birds and pterosaurs the bones stiffen the leading wing edge, but in bats the bones also allow direct manipulation of the shape of the wing. To some extent the bird 'alula' does that too. Dialata took the shape-altering wing further. The foremost digit acts as an alula too, by the way.
The one missing aspect here is ho to make an airfoil in cross section. Wings do so with feathers, and bats do not seem to smooth the wing surface over at all. I have always wondered whether pterosaurs had some 'filler' material under their skins to achieve a smooth surface. Dialata certainly do, so they do not really look like bat wings.

Abbydon: there are probably some gliding forms using membranes, like the one shown in the post. These seem to crop up in evolution repeatedly, and they do so ion Furaha troo., However, none evolved into a large stable clade, unlike birds, bats and pterosaurs (and Di- and Quadrialata).
As for publishing The Book, it is easy to produce your own book these days, but without proper distribution by a publisher it will not get far at all. I expect this to be a risky business proposition for a publisher, so it may be hard to find one. i do not expect The Book to be published soon for that reason.

Anthony: thank you. The problem with ZBrush is that you can see others do the most amazing things while you know that you have to spend a full day to try to master one aspect and may still fail at the end.
There already was a sampler, and I will probably make a new one when the book is finished. I may have to produce a sampler in Dutch for an upcoming small art exposition. I have thought about kickstarter, but what I read about it involves a great deal of social media work, which I dislike enormously.

Davide Gioia said...

"I have always wondered whether pterosaurs had some 'filler' material under their skins to achieve a smooth surface."
They did! Check this recent article https://www.pnas.org/content/118/44/e2107631118.

Keavan said...

I could be wrong, but I'm pretty sure the article is talking about muscle being used to "smooth" the junction where wing meets body, and not that the wings themselves were filled out with something.

Davide Gioia said...

"These skeletal muscles likely ran throughout the wing membrane, as has been shown for other specimens (16, 17)."

Sigmund Nastrazzurro said...

Davide and Keavan:

Well, well. Apparently that paper was only just published! I am surprised though that the fairing in this pterosaur was supposedly composed of muscles, as these are quite heavy. fat would at least have been lighter, and birds and bats use hairs and feathers, which to a large extent means hair.
As for muscles in the wings themselves: if the wing is essentially a flap of skin, it makes sense to embed the usual skin muscles to control the shape of the flap.

my name is inigo montoya said...

Of course people would call them "dragons". After all, they did call a big monitor lizard the Komodo dragon ��