Thursday 25 December 2008

The Cycle of Cyann

The title should more properly be 'Le Cycle de Cyann', as this is a series of 'bandes dessinées' (the word 'comics' does not seem appropriate) by Bourgeon and Lacroix that does not seem to have been published in English. I have no idea why, but there have been arguments with the first publisher, Casterman. The series started in 1993 in a magazine called 'A Suivre' ('To be continued'). Strangely, I did not find any good websites to direct you to, not even at the two different publishers responsible for the albums: Casterman and Glénat. Amazon in the UK and the USA only have entries for French and German versions, but amazon.fr will at least show you all the album covers. The series revolves around a rather attractive headstrong young woman called Cyann. Driven by the hope to find a cure for a disease ravaging her home planet she discovers that the priest class on the planet have kept a portal system hidden from the population, that allows travel through space. The system is largely derelict, and many worlds have been out of touch for so long that they have forgotten their common ancestry, and developed their own customs, architecture, etc. The reason to mention the series here is that the authors are rather good at making up entire planets, with ecologies, etc, along with peculiarities of their human inhabitants that really seem to belong in that ecology. Cyann's home environment is humid and tropical, and the inhabitants are accordingly dressed scantily. Except that this makes sense, it allows Bourgeon to draw attractive women, something he seems unable or unwilling to forgo anyway. There are lots of plants and animals in the series, and you can tell that much attention has gone into their design. Anyone interested in the background of the series should pick up a copy of 'La Clé des Confins', that is not a story by itself, but a companion volume explaining the worlds Cyann travels on. Here I will introduce just a little sideshow from the first album (La Source et la Sonde). The two main protagonists have camped outside and are waking up. The next page starts as follows:
Click the image to enlarge it
We are treated to part of a food web in just a few frames: there are floating seed heads, that are of coarse ballonts (see earlier entries in this blog to learn more about ballooning animals). The balloon sac is opened by some avian to get at the seeds, while a ground-living animal has another way of getting at them: it jumps up to get at them, and its hind legs seem specifically well-developed for this purpose. But make sure you look at the background as well: there are interesting plants, there is a city with intriguing architecture, the heroine is lying on the ground, etc. And all this is just a sideshow for the main action. I think I will post some more morsels of this marvelous universe every now and then.

Monday 8 December 2008

Why there is no 'walking with tentacles'... (4)

So the 'Walking Tentacle, Mark II' developed last time has a stack of elements able to withstand compression and still has considerable amount of freedom, with its many ball-and socket joints. In fact, I was tempted to elevate it to the level of a 'Working Solution' and to keep it in the Furaha universe. There are several things it cannot do that a completely muscular tentacle can do, and that is to lengthen or to shorten at will. It also still takes lots of muscle force just to keep it in place.

There are some interesting refinements to be considered. One thing I came up with is that the surface of the joints is now completely smooth, not obstructing movement in any way. But suppose that the surface could somehow be made to become less smooth if needed. Perhaps with small elements under the surface that can be raised to make the surface coarse-grained. If you do that on both sides of a joint's surface, the friction will become much larger, so the joint would need less muscle force to stay in place. That would be the Mark IIb...

But a much more likely development would be to reduce the number of movable elements. Simply lengthening the compressive elements inside the tentacle would solve many problems: there are fewer areas of motion, hence fewer places where muscle force is needed. The concentric muscle cylinders can go, as they are replaced by muscles spanning one or two joints.

But consider the nature of this Mark III 'Walking Tentacle' looks like: it is a series of elements made of strong material able to withstand compressive forces, and movement is effected by muscles pulling at these elements, causing them to rotate at some places only: yes, the Mark III 'Walking Tentacle' is a leg, and that's why there's no 'Walking with Tentacles': they evolved into legs...

Here it is, with just two muscles (click to enlarge)

Sunday 30 November 2008

Why there is no 'walking with tentacles'... (3)

Last time I argued that using tentacles to walk on would require wasteful amounts of energy. To withstand bending forces you would need very high pressure inside the tentacle in order to keep it stiff enough (the principle is called a muscular hydrostat by the way). The first big disadvantage that this generates is that you need a lot of power , and the second is it the high pressure puts a large strain on the circulation.

So let's do some creative evolution to work around these problems. A tentacle differs from the balloon animal in the last post in that the inside of the balloon is filled with air while the tentacle is filled with muscle cells, i.e., basically water. For walking purposes we need something well able to withstand compressive forces. The first thing I can see happening is compartmentalization. With compartments inside the tentacle, you could have high pressure in one compartment and lower in another. The next step is to have some organ inside each compartment that is built to withstand compressive forces. Evolution might start with specialised muscle cells, that no longer contract actively, but simply form an elastic blob that is fairly stiff, and less easily deformed than the cells.

Click to enlarge

They could have a shape as shown above: a more or less cylindrical sac filled with a jelly-like substance. Perhaps its wall is non-elastic, or perhaps there are strong fibres in there, running from one side to the other. Let's call this a 'corpus gelatinosus centralis (CGC)', or, in Latin-less days, a compression blob. Whatever the solution, the blob holds its shape, and if you stack a number on top of one another they can carry weight. It will still need lots of muscles on the outside to keep the stack balanced. Three layers are shown, but that is just a rough idea. The arrangement costs less energy to keep upright, controlling it still costs lots of energy. It might just allow an animal to fumble around on shore, so perhaps this is a credible 'Walking Tentacle, Mark I'.


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Click to enlarge

Evolution will not stop there, however. The next step is shown above. The CGC's have evolved, and now fit rather well together. The top half of each is spherical and fits in a depression in the bottom part of the next one. This arrangement ensures that pressures can be safely transferred down the stack of CGC's, called the 'columna corporum gelatinosorum (CCG)'. Take care here, as you can get lost easily in anatomical jargon. The spherical joints between the blobs allow movement in all directions, so from the outside the limb still has many characteristics of tentacles. The material of the blobs has evolved as well; they no longer simply keep their shape by virtue of tension fibres inside the blobs, but the gelatinous mass is now also crisscrossed by calcareous spicules that withstand compression forces directly.

Circling the blobs the various layers are still there, but with two innovations. The first is that there are now ligaments as well as muscles that attach to one blob and connect it to the next one in the line. These are crucial in fine tuning the positions of each pair of blobs, while the outer muscle layers do the brunt of the work in moving the tentacle. The second new item is that the layer of circular fibres has atrophied, as it is hardly needed anymore: it's job was mostly to generate a high tension, but those are now to a large extent taken care of by passing the forces through materials that withstand them.

I guess I should have put these refinements in the figures, and perhaps I will, at a later date. But this concludes the 'Walking Tentacle, Mark II'.

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As for Mark III, I wonder if anyone sees where this is going; we are on the way to evolve a walking tentacle, and yet the thread is entitled ' Why there is no 'walking with tentacles'...

Thursday 27 November 2008

Why there is no 'walking with tentacles'... (2)

Well, it took a while to write a new chapter. The reason is called 'work'.

Anyway, to continue with the 'Not walking on tentacles' subject, I made some illustrations with Vue Infinite, shown below. Let's have a look at a typical tentacle.

(Click the image to enlarge it)

This particular one is almost entirely made up of muscle cells (also called muscle fibres). the fibres are the red elongated structures. I played with images of mammalian striated muscle cells to form a reasonably realistic texture. The first thing to remember is that muscle fibres can only pull; they cannot push! So, if we want to use a tentacle as a leg, pushing against the ground, we will have to devise a way to push with elements that can only pull. Normal legs, with skeletons, work because the two jobs are separated: the muscles pull on the bones and the bones do the pushing.

Back to the tentacle: it is almost entirely made of muscle cells, except for the very centre, where I have put in an artery, a vein and a nerve (these have the customary colours found in medical textbooks: the artery is round and red, the vein is rather floppy and blue, and the nerve is solid and yellow). No bone, of course; it wouldn't be a tentacle if there was one!

The muscle cells are arranged in concentric layers, and the muscle fibres are arranged in different directions in different layers. The innermost layer has its fibres running lengthwise. If they contract, the tentacle will shorten. It will also become thicker, as the total volume of the tentacle will not change; after all, the whole thing is largely water, and water is incompressible. You can also have the fibres of that layer contract on one side only; if that happens, the tentacle will bend. You do not have to have this happen along the entire length, so the bend can happen anywhere. Already our tentacle can move in various directions.

The outermost layer has its fibre running transversely. If these contract, they will squeeze everything inside. Having nowhere else to go, the tentacle will become thinner, and therefore longer. The two other layers were added to add a bit of complexity and dexterity: their fibres run diagonally, so they will tend to twist the fibre. They also have compressive as well as shortening effects. Playing with these layers and fibres should allow the tentacle to move in just about any way you can think of.

There is no particular need to have the layers arranged just so. In fact, there might be another lengthwise layer on the outside, and there are various other things you can think of. As it stands, the tentacle can pull quite well. By activating the circular fibres the tentacle will become longer; isn't that the same as pushing? Well yes, but not with any great force. What we have so far is something like the human tongue, and you can push it out of your mouth, or against your teeth. But you can't do push-ups with it.

(Click the image to enlarge it)


To understand why, look at the balloon animal shown here. Its 'legs' sacs of air, and the only reason they hold their shape is because the sac under pressure. If we do the same for the tentacle, and tighten the outermost layers of the tentacle over its entire length, the inner bits of the tentacle would be under pressure, with the same result: a structure with enough tension to hold its own shape. But you cannot put any weight on a balloon animal: the legs buckle.

With that as a given, the simplest solution is to increase the pressure tremendously, so the leg/tentacle will not buckle so easily. That seems to be the solution chosen for the 'megasquid' in 'The future is wild'.

But that is so wasteful! The tension has to be built with continuous muscle force, and that eats energy. In contrast, to stand on bones the only energy you need is to keep them from buckling at the joints, and if you balance them right, all you have to do is a balancing trick rather than a brue force approach. A second problem is that the pressure inside the tentacle would be very high, and that creates big problems for getting any blood to the muscle cells. Blood pressure in the tentacles would have to be even higher than tissue pressure to force any blood through, and that in turn puts heavy strain on the heart, or hearts, come to think of that. More energy, more engineering problems. Anything with bones would run rings around such silly squids.

I think walking on tentacles requires more than a very thick tentacle; it needs evolution to keep the costs down. More on a possible solution next time...

Monday 6 October 2008

Just some tree designs

Real life has a habit of getting in the way of more creative endeavours, so any trusty reader will have to wait a bit for me to write some more on how not to walk on tentacles. Meanwhile here are a few trees I have been working on, which perhaps also counts as creative work. They are designed with XFrog, and rendered with Vue (links in the appropriate section of the website). As always, click on the images to enlarge them.



First, this might either be called a Thistle Tree or a Galactère. It's surprising how quickly the number of polygons rises: this version weighs in at over 1.1. million polygons, and I don't think the ratio of leaf size to tree size is good yet: the leaves should be smaller in relation to the tree, but that is the quickest way to get really high polygon counts.


Here is the same tree shot from underneath, which perhaps helps to understand how it got its names. You can get away with much rougher leaves for long distance shots, but if you want to get in close you need detail.



And just for fun a Mollum, that is rather unlikely to make it through the utterly unnatural selection process determining continued survival on the planet Furaha, also known as Nu Phoenicis IV...

Tuesday 23 September 2008

Why there is no 'walking with tentacles'...

Tentacles are cool: they look sleek, effective, a bit mysterious, and also slightly repulsive, particularly when covered with lots of suckers and slime. It is no wonder that science fiction illustrators equipped their creations with tentacles when something like the above-mentioned criteria were called for. And longer ago monsters like the 'Kraken', a giant octopus, were the staple monster of heroic tales.

As an aside, it is interesting to speculate why exactly the boneless movements of an octopus evoke fascination as well as revulsion (not in me, but certainly in many people). The explanation might be that their body scheme is so completely different from ours that it is difficult for us to comprehend what is going on when they move. (there are neurons in the motor areas of our brain that respond when we see body parts moving in other people; I would predict that their response is less as a body scheme departs more from ours). But that is not the point here. Let's take it as a given that tentacles create interest, so it would be nice to design some creatures that walk on tentacles.

Those who really know their cephalopods might say that there is no need to design animals walking on tentacles, as they already exist. Indeed; here they are. But those are 'walking' underwater, and I want animals walking on dry land.

Before anyone thinks of the loophole that land animals could quite well walk on tentacles in a very light gravity, I will accede the point. But I want animals walking on dry land in an Earth-like gravity.

Some among you might now think of ballonts (see earlier entries) that are starting to evolve back to a terrestrial life again, so they can walk with their bodies partially suspended from a balloon. To stop that, and lighter than air parts are now declared officially out of the question. The demands put on this design are to walk on tentacles in an Earth-like gravity on dry land, without any unfair ballooning aids.

I will count the solution of having a very very large number of legs as a possibility, but it doesn't sound energetically efficient. So try to design the biomechanics in such a way that the animals could actually work.

Has this been done? Well, yes. In fact, I designed one many years ago (in 1982...), turning one tentacle in a slug-like foot, leaving the others free. It was the Jellyshell, and here is part of its description:

"Without any apparent reason they will suddenly set out towards the beach. Many specimens crawl ashore more or less simultaneously, move around for a while on the beach, leaving trails of glistening slime behind them. These mysterious maneuvers last for several hours; afterwards they return to the water and take up their normal habit of slithering and algal grazing. They will not be seen on land for weeks on end; then you will suddenly encounter dozens of their trails on the beaches, left during one of their forays. Just why they come on land, and why they glide and slither there in their slow and solemn way, no one knows."


But having one slug-like foot doesn't really count as walking, so I guess that one does not count. Dougal Dixon did one several years later: the 'Coconut Grab' (found in 'The New Dinosaurs' from 1988). Here it is (click on it for a full scale depiction; it is fairly large). I think the book is still to be found, and I definitely recommend it.


That comes much closer to 'walking on tentacles', but not close enough: as the description says, the grab draws itself along the ground with four of its legs, and crawling doesn't count as walking.

So the only ones I know of that really count are the evolved cephalopods in 'The Future is Wild': the megasquid especially. This was a television series that featured some speculative evolution. The megasquid is a gigantic descendent of squid (probably octopuses, come to think of it), and it walks upright on its eight columnar tentacles. The program does have some comments on how the legs actually work, and these make it clear that the tentacles are properly boneless, as they should be. Here is a frame taken from the program.


I have my doubts though; is the proposed bimechanical explanation sufficient, or, to be more precise, would evolution leave it at that?

But first some explanations are needed about what makes a tentacle into a tentacle; but that's for another installment.

Sunday 7 September 2008

Ballonts II

(No, there is no 'Ballonts I', but there is an entry on 'The Interplanetary Zoo III', and that could have been called 'Ballonts I').

I guess that ballonts could do with a bit more attention. Let's start with a small illustration of their physics. I made the point that ballonts work better in heavy gases, meaning that you need a smaller gasbag to lift a given mass in a heavy than in a light atmosphere. Or, you can lift a heavier load with the same volume of gasbag; same principle. So here is a mixomorph larva. Its gasbag, as well as the gas, are supplied by the parent. The larva merely floats suspended from the gasbag. There is complete painting of them, by the way). It floats around passively until it lands, and then the larva can wiggle around for some time to find a suitable spot to root in, and there it remains for the rest of its life. Of course only one of these sketches depicts the real larva: the middle one. The one with the spindly larva shows the consequences of a light atmosphere, and the other one is its hypothetical heavy air cousin.



Playing around with this principle results in a series of organisms from different planets. At the top right you will find a ballont from a light atmosphere. With its large gas bag it is reduced to floating at the mercy of the winds. It does not even have any limbs for transverse movement, as these would be futile. Going down and to the left the gasbag gets progressively smaller. These animals live in heavy, soupy atmospheres. Locomotory limbs, i.e., wings, begin to appear, and these progress from thin weak flaps to sturdier shapes. At the end, just above the gray line, the difference in density between the gas and a fluid isn't very large anymore, so the animal takes on some characteristics of aquatic animals, such as wings that are almost flippers.

The gray line is literally a watershed; below it, we are dealing with fluids, and the shift in density is so large that the gas bag can be extremely small. In fact, it is hidden inside the animal, and is now known as a swim bladder. Gasbag or swim bladder, wings or flippers, they are the same things, really.

Wednesday 13 August 2008

The Interplanetary Zoo III





More Edd Cartier! Once again, you can see that there were some really good aliens 50 years ago.

This time, it's a ballont. A what? You heard, a ballont. Or perhaps the word is new to you, as well it might be, seeing I invented it. It is meant to describe all lifeforms that fly, or float as the case may be, due to being lighter than air. All heavier-than-air flyers are labeled 'avians', even if they do not look particularly like Terran birds. Terran insects are avians too in exobiological jargon, like it or not.

Do ballonts make any physical sense? At first glance, they might not, seeing how on Earth man made balloons have to be enormous to lift just one human up into the air. Could such a design be made out of living tissue? In that case the lifting gas inside, no matter whether it is a light gas or hot air, would have to be supplied by the animal. That is no mean feat, and would probably require a significant energy expenditure, requiring heavy organs, making it impossible to lift them, etc. Even if the sac itself were made of dead tissue, not requiring any energy, and if the lift would be generated passively, for instance by being kept hot in some way by the sun (by being pitch black perhaps?) there still is the problem that there is virtually no way to move against the wind.

No, the thing is to adapt the circumstances rather then the organism. Would you consider a fish as a ballont? Probably not, but you would be wrong conceptually (you would be literally right, as fishes do not fly in air). If the fish has a swim bladder, it manages to float passively in the sea; it does so because it, as a whole, is just as heavy as water. And yet the fish itself, with its bones and its muscles, is made of material heavier than water. It is the swim bladder that is much much lighter than water, being filled with air. The combination allows the lifting forces supplied by the swim bladder to balance the sinking forces due to its heavy body: the fish floats...

The reason why fishes work and ballonts do not (really) resides in differences in mass: the fish isn't much heavier than water, but its bladder is much lighter than water. That's why a small bladder can lift a big fish in water. For a human in a balloon, the human is much heavier than the air, while the contents of the 'bladder', the balloon, are only a bit lighter than the air. Hence, an anormous balloon is needed.

The lesson is that ballonts will work better in heavy gases. That's why SF authors have them floating in gas giants. In the Furaha universe, ballonts in gas giants are so ubiquitous that people are completely bored by them. "Oh no, not another documentary on ballonts..."

Having ballonts on a terrestrial planet, a Gaean such as Furaha, that is a novelty. On the website there is I think as yet only one, on the splash screen. I am afraid to do the math, as I am afraid I will have to strike them from creation, and I rather like them.

Look at Cartier's ballont. You can see he understood the metabolic difficulties of the design: the limbs are frail and light, and most of the animal is in fact no more than a sac. You could probably work out the heaviness of its atmosphere by comparing the volume of the sac with the mass of the rest of the body. Fairly heavy, I would say; definitely not living on a Gaean.

Thursday 31 July 2008

Texturing the planet

Finally the work of making a texture for Furaha is nearing completion.

After ample deliberation I decided upon places for likely deserts, based on some understanding of Earth's climate system. I did receive help, but in the end I confess there was lots of guesswork. It was good to have that major hurdle out of the way, as I could then concentrate on creating the texture itself.

To do that, I needed to become more used to Photoshop (never mind 'proficient'). In the end I took published maps of Earth (NASA's 'Blue Marble' series), and I cut bits and pieces out of these maps, and pasted them, with some rotation if necessary, on my new map. I used some of Photoshop's tools to bridge the borders between these pieces with believable intermediaries. That took some time, mostly because I was learning this as I went along.

Having done that, it was time to create some shallow seas, done by lightening a few pixels here and there near some coasts. And there we are! The real texture is much bigger than shown here, by the way. It is probably much too light, but that was handy during construction to see what I was doing. Compared to the Blue Marble pictures, this texture is much too bright, so it will probably has to cross over to 'the dark side' before I post it on the website.


Click to see in a bigger window

That's not all though, I also worked on a programme to cover part of the land with snow and ice, depending on the season. You can see the result for Earth below. I can of course do it for Furaha, but the advantage of doing it with Earth is that the result at least allows an idea of how well it all works. The programma works by taking the distance from the nearest pole (latitude) as well as elevation into account. These are combined in such a way that the chances of snow cover are bigger as you come nearer the pole and as you get higher up.
The same is true for the Earth: mountain tops may be covered in snow when there is no snow at all in the surrounding valleys, and the nearer you get to the equator the smaller the chances of finding a snow-covered peak are.
Where the program goes wrong is in forgetting about precipitation: the definition of a desert is a place with very little precipitation; and when there is no rain or snow, you do not get an ice cover, no matter how cold it is. The Tibetan plateau may be such a place: there should be no snow, but the programme puts it there. Oh well; that can be edited.

Click to see in a bigger window

What's left? Well, rivers, lakes, sea ice that changes with the seasons, seasonal changes in the colours of the land due to plant life, etc. Much to do yet...

Sunday 20 July 2008

The Interplanetary Zoo II


It's time to bring another of Edd Cartier's wonderful drawings back(I've found about 10, so we haven't run our yet)

Now thís is really an odd design. People who design alien lifeforms often try to get away from the shapes we know to enhance the alien nature of their designs. I have my doubts how far you take take that line of thinking, because biomechanics will work the same all over the universe. If you wish to swim, streamlining is efficient, given certain characteristics of size, density of the fluid, etc., etc. Leave that as it may be for the moment, and approach the problem from a different angle: perhaps an alien design works as such if you cannot immediately work out what the general build of the animal is. If you wonder 'how does this thing work?', then the designer may be onto something.

Like the previous one, this creature seems to have a rotund body slung between two walking limbs. The limbs divide in separate parts, but that is nothing novel: our legs also end is toes, and the prototypical arthropod limb also is 'biramous', meaning it has two branches. But this one is slightly different, in that the split into 'toes' happens fairly high op the limb itself, so the 'toes' take on an aspect of legs themselves. They seem capable of somewhat independent motion. If our legs would split into two separate 'leglets' at the level of our knees, would we say that we had two lower limbs or four?

Never mind, but the point is that this is a shape that takes some study before you start to see how it works. As such, it's delightfully alien.

Thursday 17 July 2008

Rhinogradentia III

The previous post on the Rhinogradentia mentioned the book by one 'Karl D.S. Geeste' entitled 'Stümpke's Rhinogradentia'. It turned out that Geeste and Stümpke are in reality one and the same person, who in real life is called Gerolf Steiner. This puts the interview, in which Geeste questions Stümpke about how the Rhinogradentia came into being, in a new light: in essence the interview is an autobiographical style figure. There are only a few pages about the early history of the Rhinogradentia in the book, but they have something to tell.

The overall feeling you get from the Rhinogradentia is one of good uncomplicated fun, without any cynicism or sarcasm. There is hardly even irony. It is all extremely good-natured. Even the responses to letters Steiner received from people who had failed to get the joke, or who felt that scientist should never joke in such a way, show a great deal of respect for the sentiments of the senders, even when these were rather dour. And yet, the circumstances during which the Rhinogradentia were conceived were not nice at all. The following is from 'Stümpke's Rhinogradentia (Fischer Verlag 1988, pp 64-67).

The project started by chance early in 1945, in Darmstadt, in the western part of Germany. Germany was not yet beaten but Darmstadt was occupied by Americans. There was nothing to eat, so Steiner had even tried frying snails with the last 10 grams of fat. He found that the mucus of the snails made the snails stick in his throat, so he was unable to eat them, and cried for being so hungry. Steiner, bombed out of his own home, lived in a room in a house in the outer parts of the city, less damaged by bombing than the city centre. He had some paper and some pencils there, that had survived the bombing. One day a student who wished to become a zoologist shared some asparagus with Steiner; this was a wondrous great gift. He wished to do something in return, and decided to make a drawing for her; something not too serious, but uplifting, and with a zoological theme. And that's how the Nasobem was born. Because he liked the drawing himself, he made another one for his own amusement. And later another one, etc.

By itself this story is not that surprising or that moving. But there are a few sentences describing what life was like in the suburbs of this ravaged city. These tell their own story and make you wonder how Steiner managed to evade cynicism or despair. For those who can read German, the original text follows first, followed by my translation. I tried to stay close to the original text.

"Ein bisschen satt zu essen zu bekommen, gehörte zu diesem Beglückenden ebenso wie später die Frülingsblumen oder die schönen Chorgesänge der freigelassenen Russen, die plündernd durch die Gegend zogen. Dazwischen hörte man das irre Schreien vergewaltigter Frauen, die sich -ausgebombt- in ihre Gartenhütten einquartiert hatten."

"To be able to get a bit to eat so you didn't feel so hungry anymore was one of the things that made you happy, just as much as spring flowers later did, or the beautiful choir singing of the freed Russians, who wandered through the countryside, plundering as they went. In the midst of this you heard the mad crying of raped women, who, having been bombed out of their homes, had found shelter in garden sheds."

What a contrast.

Saturday 12 July 2008

Locomotion in the game 'Spore'

'Spore', for those few who do not yet know, is a long-awaited computer game in which the player must design and guide a creature from life in some warm pond to a space-faring civilization. While there may not be that much overlap between those who play computer games and those who are interested in exobiology, 'Spore' should hold some interest for either party.

A few weeks ago a part of the game was introduced on its own: the 'Creature Creator'. If you type that into Google with 'spore' along, you will find it in no time. There is a free trial version as well as an inexpensive complete version. The 'creator' allows the user to stick various bits and pieces together to design interesting animals. The parts can be rotated, scaled, etc., and the animal can be coloured to great effect. The program works very smoothly. The resulting animals have a characteristic cartoonish shape and mode of movement to them, so I recommend playing with the trial version.

There are many things you cannot control, however. For instance, you can control the thickness of a body segment, but this works fro all dimensions of that segment. It would be hard to depict a very flat animal with this program, at least so it seems to me now. Another thing that had me puzzled was how the programmers dealt with movement: you can stick on predefined limbs, and then the animal will walk all by itself. I was interested in how the programmers had solved the problem of gait. The Furaha site contains a page on various gaits, and those who have read that will know that there are many different gaits, that all depend on the number of limbs. To see what would happen, I designed a simple animal with a sausage-shaped body, and stuck on up to five pairs of limbs.

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Let's start with the simplest design, a biped, with just one pair of limbs:


By the way, the video catch mode is built into the program; very neat! As you can see, the phase difference between the legs is exactly 50%, or indeed what you would want a walking bipedsuch as ourselves to do. I haven't sen anythingresembling gait controls, and if there aren't, there will be no way to get a kangaroo-like gait. That's a pity in a way, but I guess the complexity of gait control might confuse many players. To keep the number of videos down, I will not show you a tetrapod gait. It turns out there is only one, and it is a trot: the left fore and the right hind leg move in unison, and opposite to the other pair. Again, only a trot, so no walk, pace or gallop! Perhaps a walk could be added in the future: having a slow and a fast gait might make the species involved more interesting to look at, and it can't be very difficult to put in.

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Now, let's increase the number of legs to three; what gait will that give us?



It's a tripod walk! Nice one. The right front, left middle and right hind legs move together, in phase opposite the remaining pair. You can also view this as the phase changing by 50% as you go from to first to the second pair of legs, and from the second to the third pair.

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And now, of course, four or five pairs of legs. The result follows:



Well, well, the programmers decided to stop following that pattern, and now all legs on one side simply move together (except during turns, and designing a neat way of turning must have taken some thought). Using five pairs had exactly the same effect. Again, there is no way to control the gait, so there is no way to obtain the nice rippling effect successive small phase differences have on the general feel of how a centipede moves.

While I would like to see more control over body shapes and gait, let me stress how much fun it is to play around with this program. It really does what it sets out to do extremely well. In fact, the programmers even foresaw that some players would develop animals without any legs at all: even then you get movement of a sort. And oh yes, stride freqency seems to go down as body size goes up. I'm impressed.

Thursday 10 July 2008

Rhinogradentia II

In part two of what will probably be three entries on Rhinogradentia, let's have a closer look at some of the biology and a bit better look at the man behind the work. The book mentioned in the first part, 'Bau und Leben der Rhinogradientia', shouldn't be too difficult too find. But there was a second book, and that one seems to have been published in German and perhaps once in Japanese too, judging from a Google search for the author. It is called 'Stümpke's Rhinogradentia' with the subtitle 'Versuch einer Analyse', which translates as 'An attempt at analysis'. It was written by one Karl D.S. Geeste. My copy, the second printing, appeared in 1988.

It contains a number of essays and historical remarks about Stümpke's work, who as we saw previously did not exist. Gerolf Steiner is the true author's name. It was not until I started writing this blog entry that I found out, 20 years after having bought the book, that 'Karl D.S. Geeste' was another pseudonym of Gerolf Steiner! You may check this on the following link, a website from the university of Karlsruhe. It states, in German only, that Gerolf Steiner celebrated his 100th birthday in March of this year (2008). Congratulations professor Steiner! I never expected Geeste and Steiner/Stümpke to be the same man, as the 'Attempt at Analysis' contains an interview of Stümpke by Geeste, which fooled me completely.

So is there more biological news in there? Yes; and parts of it concern details of the plates in the Rhinogradentia book. For starters, have a look at the Nasobema and its young on the opening illustration in the last entry. What Steiner, as we now know him to be, had to add to the plate was (my translation): 'Please note the allometric growth of the extremities. The hind legs of the young animal are relatively much longer than its mother's". Indeed, and what a nice detail.

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Above is another such detail. First, the cover of a Japanese translation. The cover shows 'Orchidiopsis', an obvious example of mimicry: the animal looks like an orchid and thereby lures insects to itself to eat them.

Next, there is an image I made in which the insects are enlarged (clicking on the image will enlerge it in turn). Geeste/Stümpke/Steiner has this to say: "The hexapterate in the top right shows some primitive characteristics: paranota on the abdominal segments as well as cerci. Its larva -bottom right- with small wing buds makes it clear that this is a case of incomplete metamorphosis." Well, well; the island group where the Rhinogradentia live has more biological surprises than just snouters. There are primitive insects, and elsewhere we read about 'land trilobites'.

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Here is a final one. Something is sitting on the tree trunk in the figure above, but what is it? Surely it is nothing but an unfinished doodle? No, it isn't.

Geeste: "On the trunk in the background [there is a] Tillinellia farfalloides, a land living prosobranchial snail with collapsible pseudopods. The animal grazes on algae and lichens on trees and can glide back to the floor." He adds that the animal was named for one Tilli Ankel, otherwise introduce only as the wife of one W.E. Ankel. Language lovers will recognise the Italian word for butterfly, 'farfalla', in the second part of the animal's name. Isn't all this a bit overdone for a few rough lines in a drawing? Not really, because the 'attempt at analysis' contains a lovely drawing of Tillinellia, and here it is for all to see:

One final remark; the German text on the site of the university of Karlsruhe mentions two other pseudonyms: Trutzhardt Widerumb and M.I.Kashkina. I couldn't find anything about the former, but the latter authored a short paper in the (really existing) scientific journal 'Russian Journal of Marine Biology (2004; 30: 148-149)' on 'Dendronasus sp - a new member of the order nose-walkers (Rhinogradentia)'. There is a drawing which I will reproduce if anyone asks for it. Did Steiner in his nineties really continue his fifty-year old work? If so, how amazing! Or does this Kashkina for once really exist, as there seems to be at least one other paper by the same author possibly of a more serious nature. Am I being fooled again?

Sunday 6 July 2008

Rhinogradentia I

One of the best known examples of fictional life must be the 'Rhinogradentia'. This word, composed the usual scientific hodgepodge of word stems from first Greek and then Latin, means 'nose walkers'. And that is exactly what these odd little mammals do: they walk on their noses. If they do not use them for walking, there are other uses too: for example they catch insects with them, either by mimicking flowers or by entangling them in mucus. The one above doesn't do anything as fancy: it simply walks on its nose.

The Rhinogradentia were first described in a little book published in 1957, entitled 'Bau und Leben der Rhinogradentia' (Literally: 'Build and life of the Rhinogradentia'), written by Professor Dr. Harald Stümpke (that is what the book would want you to believe; the real author is Gerolf Steiner). The book has later been translated into English (the snouters), French (les rhinogrades), Italian (i rinogradi) and Japanese (sorry, no idea). My copy, a German one, dates back to 1981, and contains line drawings in black and white.

The book is still available, certainly in German and English, which probably says a lot about its qualities: it is still funny and entertaining after 50 years. It has received quite a bit of attention on the internet as well. It featured in the 'Tetrapod zoology' blog, not just once but twice, and there is even a Japanese site showing photographs of models of various Rhinogradentia. These look very much like the original drawings. I would be curious to read the text, but Google's translation services leave enough to be desired when it comes to Japanese to leave it unsaid.

If the Rhinogradentia have already received so much attention, is it necessary to repeat all that here? I will only go into the Rhinogradentia shortly here, and in a next instalment I will discuss a few things about the Rhinogradentia not easily found on the internet.

The drawing shown at the top depicts the first 'Nasling' designed by Steiner, so in a way it is the prototype for all others. The very first drawing may not exist anymore, as it was an aquarel given to a student out of gratitude for having given the author some asparagus (more on why asparagus was important in the second instalment). The drawing was inspired by a poem by Christian Morgenstern; it starts as follows:

'Auf seinem Nasen schreitet

einher das Nasobem,

von seinem Kind begleitet'

(Literally: 'On its nose strides the Nasobema, accompanied by its child'). Regardless of any poetic qualities, you can see that the drawing certainly does justice to the text. The word Nasobema, by the way, means 'nose walker', but here the word for 'nose' is Latin and the one for 'walk' is Greek, just the opposite of 'rhinogradens'. I guess the biology doesn't really make much sense: the animal still has perfectly functional limbs, and there appears to be little evolutionary reason to develop an alternative mode of locomotion under these circumstances. But the fun of Steiner's work is that it is so well carried out otherwise that you immediately overlook such matters. There are life histories, quotes of (equally nonexistent) scientists, and many more details to entertain the reader.

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Just one other example should wet the appetite for more nosewalkers. The drawing above shows Otopteryx volitans. The discussion starts whether it was sufficiently evolved to separate it from the other Hopsorrhines (it turns out it isn't), and then delves into its flying habits. It flies backwards... Landing and taking off are disussed as well, which is proper if you start thinking about it: flipping the tail downwards and backwards must have some interesting aerodynamic effects! The text states that its fur glistens so much that it resembles a humming-bird.

The other two drawings show the love of detail. I left the legends in, even if not all readers can read the original German text, simply to give a feel for the work.

The next instalment will provide a bit of background. To end this one I would like to report something of interest: while searching Google, I came across this intriguing mention: apparently someone in 1970 named a real butterfly species 'Rhinogradentia steineri'. So they do exist, in a way...

Tuesday 3 June 2008

Too few hours in a day...

...meaning I can't do a weekly update just now. However, I am preparing a post on walking on tentacles: not a good idea.

Sunday 25 May 2008

Droodle


Still working on a good texture map. It takes quite a bit of time, so little time is left to post anything here. Still, the Droodle from the previous post may deserve to be seen.
Any takers for its name?

Monday 19 May 2008

The 'Oh dear' sensation

Not much time to write a new entry in this blog. Let's just see what it takes to improve the quality in the fields needed to produce a nice and interesting book on Furaha:

1. Photoshop!
It is time to make the transition from painting in oils to purely digital art, I guess. Perhaps not so much to produce new main paintings, because doing those digitally would clash with the style of those already done. But each main painting could probably use a few nice instructional diagrams, close-up views, views of related species, etc. Those could be done digitally.

2. Blender!
Blender is a free 3D design programme. Expanding the human interest on Furaha means I need to do more work on people. Sofar they are hardly visible. I will also need some buildings, and chiefly some vehicles to show on expeditions. For that a good 3D-application will be needed, so I have started working with Blender.
It is clear, however, that designing a range of appropriate mass-repulsor floaters will take some time. 'Mass' what? 'Mass repulsors': a technology with which you need a reaction mass to lift slightly more than that mass itself. They are fairly cheap, and do not require much energy to keep them floating, but that is the best you can say about this tech. As the efficacy factor is only about 1.01, you need a mass of about 10,000 kg to lift a useful mass of 100 kg, or one human with some equipment. Think of a machine the size of a steam locomotive, but filled with concrete or metal scraps, but much slower, and with all the inertia...

3. Indesign!
Lay-out and design software. I think I would probably have to design a at least a few sample pages to show to potential publishers. I've opened a demo version of Indesign, but that's about it.

3. More species!
You can never have enough species. I really need to do a big image of a rusp. Clografts would also be good (that's clog-rafts, not clo-grafts) .

4. Cladograms!
I need cladograms. Those shouldn't take too long, at least not if I do not work out each and every group of species. Meaning I can make branches that won't be accompanied by many drawings.

5. Textures!
Well, I am working on a texture, and am beginning to force Photoshop to do what I want.

I do not really dare to put time estimates on all these tasks. Sometimes you just have to begin. But there is a slight sensation of 'Oh dear' involved, which by the way conforms to one of the limited number of emotional states of the Droodle (Lorica segmentata). The others are 'wet', 'dry', 'cold', 'warm' and 'Oh shit'.

Monday 12 May 2008

'Textures'


The maps of Furaha are at present available in two forms: a line map showing coasts, and a pixel-based map showing elevation. Both were done in Matlab, allowing myriad different projections and many display options. The pixel-based one has 4320x2160 pixels, meaning it has a resolution of 5 minutes of arc. In the neighbourhood of the equator that's about 11 kilometres per pixel. Not bad, but not very detailed either.

Unfortunately, there's one thing such maps cannot do, and that is to show the planet as it looks from space. Height is one thing, but colour is another. NASA publishes great maps of what Earth looks like as seen with satellite imagery. What these show you is that seasons make a difference, which isn't too surprising, and also that deserts are yellowish and the rest of the land is green, varying from bright green to dark green and grayish green. Height is only important in that it is more likely than other regions to be either snow-white or desertlike in colour.

Others have found their ways to such data stores as well, to give their fictional worlds that realistic look. Some great examples can be found at Celestia, a program allowing you to zoom through space and have a look at realistic and real objects. At the Celestia Motherlode you will find objects made by users that are equally realistic but as unreal as the others are real.

How do they do it? You have to paint a 'texture', meaning a colour image of what the image of your planet would look like. The best way to do so is probably to 'borrow' bits of Earth texture from NASA, shift and rotate them, and paste them together to obtain a good result. That sounds easier than it is, and many hours of work go into a good texture. I have just started work on a Furaha texture. I decided that this was a good accasion to learn to use Photoshop anyway. My first experiences with it are frustrating: nothing works the way I want it do, and nothing is where I expect it to be. This is probably my punishment for not starting to use it many years and versions ago, when learning it was more or less manageable.

The good news is Celestia. At least that program, which is completely free (!), allows you to obtain a quick and rather good looking rendering of your texture. Generally you just hijack Earth's or Venus' texture and replace it with your own, and, voila, a realistic rendering. Earth is shown at the top of this post, and my first attempts at Furaha follow.



The golden sheen means that the 'texture' is just a monochromatic yellow rectangle. Still, you can see how Celestia makes land dull and oceans shiny, and uses the height map to good effects in that it helps form lighting and shading effects. The final image, below, shows an extremely rough Furaha image, with very coarse colours. The clouds make a big difference though, don't they ('borrowed' from Celestia's Earth map...). By the way, if you are surprised by the spelling, Celestia somehow figured out I am in the Netherlands, so it changed its language to Dutch, but with a distinctive Flemish spelling.


Oh yes, to do it right, I still have to figure out where to place deserts, and to that properly I need knowledge of climatology. Which I haven't really got, so it will have a be a hopefully reasonable guess...

Sunday 4 May 2008

Glapum'tians

There are many interesting animal designs in fiction. A specific supply that may not be well-known in many parts of the world are SF and fantasy comic stripe in France, There, comic strips are found in large numbers in book stores, bought by young as well as adult readers. However, their flavour is different enough from what you will find in other parts of the world to not to call them comic strips or graphic novels, but simply 'bandes dessinées', or BDs for short. I thought I might start with an old favourite, an intelligent creature from the world Glapum't; hence he is called a Glampum'tien in French, which would probably translate to a Glampum'tian in English (I have no idea why the apostrophe is doing there, but presumably it is doing the same thing it always does in SF, and that is make names sound more alien). Glampumt'ians can be found in the BD series 'Valérian et Laureline', running since the late 60's; it now numbers 20 albums. The scenarios are written by Christin, and the drawings are by Mezières. The protagonists are space/time agents from the future. In the course of the series they have been through many adventures, always with a human outlook on things, a degree of feminism (Laureline is usually the one who solves the problems) as well as mild social criticism. There was never much 'hard' SF in the sense that technology featured much. Instead, the series has always been about people more than anything else. The same goes for the designs of its aliens: great fun to look at, and no-one cares much about their believability. In the course of the series the world was destroyed in 1986 in an album written before that time. As that time approached in real life the story went through some intriguing twists to reconcile the real history of the Earth with the storyline. Even later the previously assumed future history of the Earth, which had become a galactic force to be reckoned with, was more or less erased, so Valérian and Laureline are now on their own. For those who want to know more, Wikipedia has a section on 'Valérian and Laureline' that includes references to English translations. All albums can be obtained in French through amazon.fr or through fnac.fr (and probably through other outlets). Time to discuss the Glapum'tians, or Ralph, as he is the only Glapum'tian we get to know. He first appears in the album 'Les spectres d'Inverloch' (the ghosts of Inverloch). Ralph is the individual with the large flat head in the left background. He caught my attention by looking quite different from most of the other intelligent races that inhabit the series, lmost of whom look roughly humanoid. Ralph doesn't look like that; if anything, he is like a cephalopod in having a head that merges with the body without any neck, and his tentacles are attached to the body directly. The painting at the top of the page and the one below provide a better view of Ralph. Both were scanned from the book 'Les habitants du ciel' ('The inhabitants of the heavens'), showing paintings and providing biological details of many species occurring in the series. This is in fact only half a painting; it was a two-page spread, and scannning the entite painting results in an ugly stripe in the middle where the pages come together. The text in that book describes Glapum'tians as oviparous mammals living on their birthing nest (that's the round shape sticking out of the water); additional texts and drawings refer to this as an egg as well as a habitat, and show it to be a living form. Intriguing (is it an organism in its own right?), but no more details are given. I rather like the Glapum'tian body shape, which looks rather elegant. As is typical of this series, there is no attempt to make alien species truly alien in the sense that their motivations are out of the ordinary. Quite the contrary, greed, power, influence and sex are common motivations for all intelligent lifeforms here. The same goes for their emotions, easy to read for us Earthlings. This is true for Ralph as well: his eyes betray his emotions exactly like a human's would. But think about the trouble the writer would have if he designed a completely different system: how do you explain it to your public? The picture here shows Ralph, a natural amphibian, under water. If you start thinking about his shape, you start to wonder how he can be a good swimmer: there are no clear propulsive adaptations in the sense of flippers, a fluked tail, or any flat surface at all. Then again, octopuses don't have such visible means of propulsion either, but they have their own jet propulsion: the siphon. Perhaps Glapum'tians have one too, but it isn't visible... As far as walking on land is concerned, Ralph's tentacles might work, but they would be very costly from an energy point of view. After all, bones are very useful in that they limit the number of points that have to be controlled by muscle strength, greatly reducing energy expenditure. Anyone who has ever seen an octopus on dry land will understand why a skeleton is beneficial on dry land: the poor octopus resembles a puddle rather than a graceful animal. Still, Glapum'tians aren't the only animals for whom a cephalopod design was adapted to live on dry land. In the television series 'The future is wild' there are land-dwelling cephalopods, including the 'megasquid', walking around on 8 tentacles. The website on The Future is Wild has this to say about their design: "an invertebrate, meaning it has no backbone or skeleton, it has strong muscles in its 8 thick legs. These need to be strong enough to support such a large body." Well, yes, but how and at what cost? Without a good explanation, the question becomes one of guesswork: wouldn't evolution kick in an adapt these 'legs' to become more efficient? Perhaps 'Walking on tentacles' is a good subject for this blog, but not now. Meanwhile, allow Ralph to swim with orcas. He does that, and enjoys talking with them, in the album 'Les foudres d'Hypsis' (the wrath of Hypsis').

Sunday 27 April 2008

Tetropters

Those who visited the land and sea pages on the site may have wondered why there is no page on the biomechanics of flight, seeing there are pages on 'Walking with...' as well as on 'Swimming with...'. So where is the 'Flying with...' page?

The simple answer is that I am not happy with it yet. There is material on ballonts and on tetrapterate (four-winged) large flyers, and some are in fact shown on the 'air' page. But these organisms are fairly like Terran birds. For a true oddity the tetropters should be considered; in their case, 'oddness' does not reside in them having four wings. After all, Furahan tetrapterates and Terran insects also have two pairs of wings, i.e., four wings, so that isn't really extraordinary. No, the ordinariness resides in the description: 'two pairs of wings', and that says it all: the wings are arranged in pairs. Insects and birds (and Furaha tetrapterayes) all have a body scheme with bilateral symmetry, so their limbs are arranged in pairs.

Not so the tetropters. To be honest, the very first sketches I did of them did show bilateral symmetry. The top animal in the following image shows that primordial tetropter. In fact, their wing movement patterns had already been worked out, and showed a pattern that was exactly the same for each wing. So the wings showed a radial pattern, like a four-pointed star, but the body hadn't kept up. Here is one of those early tetropter designs under attack from a larger tetrapterate.

With their radial wing pattern tetropters were excellent hoverers, and control over wing movements should have allowed omnidirectional movements. But the animals still had a front and aft side. If you have a flight system that allows such tremendous manoeuvrability, why limit it with a limited body design? That is where the concept of complete four-sided symmetry came from. The next sketch illustrates the next logical step in the evolution of the tetroper concept. The top animal has bilateral symmetry, but the bottom one represents a conceptual novelty: the body follows the wings! So the entire animal now shows complete quadriradiate symmetry. By the way, I was taught that you should not mix Latin and Greek roots, and that is explains the switches between 'tetra-' (Greek) and 'quadri-'(Latin). Can't be helped.


I know of no such designs on Earth, although there are animals with five-sided symmetry (starfish, sea urchins etc.). The rest of their body scheme hasn't been worked out in much detail. The design problems are like those of octapods, with eight-sided symmetry. Tetropters too have eyes above as well as below their 'equator', and the mouth parts are all on the ground side. But I haven't done a complete drawing or painting of one yet, so the details remain sketchy - for now.

I found that the flight patterns had much in common with the movement patterns of flying and walking organisms. After all, each leg or wing or flipper moves repetitively, and any gait is no more than a cycle in which the limbs move with a specific set of phase offsets. Although there are an infinite number of ways in which you can do so, only a limited number make much sense. And so tetropters have 'walks', 'trots' and 'paces'. The first pattern shown here is a rather silly one.



I can't show the animated gif here; to see it click here.

Imagine the sphere as the animal's body, seen from below and to the side. The four wings are rotated around their axis to provide lift while going clockwise as well as moving back anticlockwise. While such a pattern does provide lift, it would also result in a net rotation effect on the animal as a whole, which is impractical. To offset that, the rotation forces need to be cancelled by having two wings swing in the opposite direction from the other two. A rough animation of just such an effect follows:


I can't show the animated gif here; to see it click here.

You can see the wings going through one another; in reality they would of course not do so. That's why I need to do a better animation, but it is not as easy to do as it sounds. In the smallest tetropters the wings clap against one another and then to move in the other direction. Many Earth insects use this technique, by the way: the clap their wings together behind their backs, and this apparently generates lift when the wings move away from one another again. In insects, there is just one such 'clap' in each cycle. Tetropters have taken the idea one step further, and the clapping occurs twice in a wing cycle, not just once.

Larger tetropters usually avoid clapping the wings together, so they reverse direction without touching. Whether this is aerodynamicaly better or simply avoids damage to the wings remains to be seen. There is so much to be researched...

Thursday 24 April 2008

Edd Cartier

Every once in a while I will show a painting or a drawing of an alien, a dinosaur or other extinct life forms that I find particularly appealing.

The first one is a drawing by Edd Cartier. I first saw it in the late seventies in a book called 'Science Fiction Ideas and Dreams' by David Kyle. The legend simply said 'Two aliens drawn by Edd Cartier for "The Interplanetary Zoo" in the Gnome Press anthology'. I wondered for a very long time how many such animals were in that book, other than the two I could find.

Today, of course, Google helps: The drawing appeared in a 1951 book called 'Travelers in Space'. here is the cover as shown on Wikipedia.


A page by David Kyle on his career in SF resulted in the following: 'I collaborated with Edd Cartier in several ways, the best being the illustrations for my story of the "Interplanetary Zoo"; this was an interesting project because the full color signature or folio in the anthology Travelers of Space was actually done from black-and-white drawings. All color was laid in by a talented printing plant technician who worked with me for the final results.' That is interesting, since it shows that the original drawing must have been in black and white.

More searching revealed a number of drawings from the book on a Japanese site.
The drawings there all have a very strong yellow background, which was not present in the book I first saw the drawing in, so I guessed it was a later addition. I mostly took the yellow away again, which brings the colours out more.


I still find this creature very appealing: it looks pensive and rather serious. Somehow it doesn't actually look very alien to me, or is that simply because I have known the image for long enough to have become familiar with it? Much as I like it, from a biomechanical point of view it is odd. What seem to be arms and legs at first glance turns out to be just one pair of limbs. These are attached to the body with what look like shoulders. In effect, the large head and small rump are suspended between these limbs. The creature must be top-heavy, and it can't have been a very elegant walker. The legs are wide apart, and it doesn't look as if its hands (feet?) can bend inwards enough to be placed directly underneath the body. That's a pity, because if you cannot do that, and still want to walk around on two feet, waddling is the only way.

Its restful appearance might be ruined if it starts to walk: it will probably draw laughs for the same reasons waddling ducks and penguins do (why is that, by the way?).