Saturday, 15 February 2014

Dougal Dixon's Microplatia; part II

The previous post dealt with an unknown project by Dougal Dixon meant for the Science Museum, and today's post will deal with the rest of the project.

First, I must rectify something I wrote previously. The 'bones' of animals on Microplatia are very springy and tend to curve in one direction; they are curved the other way by muscles. On Earth, vertebrate and arthropod limbs with a joint with one direction of movement need muscles pulling the bone or segment one way and other muscles pulling the other way. On Microplatia here are just two elements: a bone curving one way and a muscle pulling it the other. The fact that such bones can bend poses interesting problems regarding their capacity to withstand compression, as you would not want to load a bent bone too much. Then again, quite

Anyway, I assumed that the tube slung under the fishing rods of the Walkingmouth would represent the muscle, but I was wrong. Dougal remarked:
"The 'muscle and spring' arrangement is not visible. The trunk-like organ below the 'fishing rod' is merely the gastric tract. All the musculature involved in casting out the 'fishing rod' is contained within the body of the beast. So the action involved is just like that of an angler casting his line. The 'muscle and spring' arrangement is better seen on the bubbles-on-stilts; I attach a sketch and the photo of the model (now alas lost to me)." 


Click to enlarge; copyright Dougal Dixon
Before we go on to 'bubbles-on-stilts' I will post the remaining sketches of the Walkingmouth. The one above shows some surface structures. I rather like the idea of a 'mother of pearl' type iridescence.  I have considered painting an animal with such a surface myself, but will need to study the visual appearance of mother of pearl in more detail before I can paint that in any believable manner. I wonder how the model makers charged with building model Walkingmouth for the Science Museum exhibition would have solved that problem. As far as I know there is no paint that gives that effect.

Click to enlarge; copyright Dougal Dixon
Here is the next picture. It shows that the animal is equipped with three slug-like feet. This image is also the first to show the animal's eyes, placed on the front below the 'fishing rod/gastric tract' ensembles.  I will just call it a 'tackle' to save words.

Click to enlarge; copyright Dougal Dixon
Moving on... literally, in a way, as this sketch shows how the tackle can move: it is interesting that the text says the bow is being 'cast'. I would expect it to be deployed slowly and deliberately, but the image of these five tackles flying out and being reeled in slowly is appealing and quite alien.

Click to enlarge; copyright Dougal Dixon
Here is a mouth unit, of which the animal as a whole will have five. I think that the structures that look a bit like scimitars in their overall shape are examples of the 'bone/muscle assembly', with the bow forming one curved edge of the structure while the muscles fill the concave side. There seems to be a scraper on the underside of the mouth. I see four small 'limbs' near the mouth, two vertically and two horizontally, while further along there are two much larger limbs on each side. My guess is that four smaller ones are there to manipulate food into the mouth, and that the four large ones are the ones that actually walk the mouth over the ground. I wonder what types of food the Walkingmouth eats. If I am right in thinking that the lower 'jaw' is a scraper, its food might consist of animals secured to the substrate such as clams. Then again, plants need to be freed from the ground too. That's all I can show you of Walkingmouths.

Click to enlarge; copyright Dougal Dixon
Another body plan resembles a Walkingmouth turned upside down: the bubbles-on-stilts. The sketch above shows a few; they remind me of Wells' Martian tripod walking engines because of their overall shape.   There are four here, which certainly helps to make their gait a lot easier to imagine than if there would have been three only. Then again, the order in which their legs move is probably the easiest thing to visualise as far as their legs are concerned. The nature of the 'curving bone plus muscle' arrangement is well visible here. Each walking legs apparently consists of a large proximal segment and a smaller distal segment curving the other way; we might as well call it a foot. The front view shows that the animals are quite narrow. That is not surprising at all; if you look closely at many large mammals, including elephants, you will find them to be quite narrow in relation to their other dimensions as well. The build of the legs must say something about the internal structure of the curving bones: their direction of bend depends on their own curvature and the muscles pulling on them, but they must be ery resistant to bending in other directions as I see no muscles controlling their curvatures in other directions than the front and aft one.

Click to enlarge; copyright Dougal Dixon
Finally, here is a photograph of a bubble-on-stilt model. It shows the translucent carapace covering the body quite well, as well as the structure of the legs. The reddish parts of the legs have considerable size in the fore-and aft dimension, no doubt to provide leverage for the muscles.         

It is a pity the model was lost, and a greater pity that the exhibition, perhaps with an accompanying book, was not realised. There are not many projects on Speculative Biology that actually make it to the stage of a book of a television programme, so each one counts. I would have liked to see more of Microplatia, and am visualising a mother-of-pearl Walkingmouth in crystal-clear sea water, gobbling up pearly clams. I wonder which kind of animal in turns feeds on Walkingmouths...
a few vertebrate bones are not held vertically when loaded, and I see no reason that such bones could not be bent. As always it will depend on the mass to be carried relative to gravity.

13 comments:

Andrew Broeker said...

"their direction of bend depends on their own curvature and the muscles pulling on them, but they must be ery resistant to bending in other directions as I see no muscles controlling their curvatures in other directions than the front and aft one."

Forget the bending resistance, how could these Bubbles-on-stilts navigate terrain without the ability to control the lateral placement of their footsteps? Are the two 'joints' really enough control foot placement along the direction of movement, allow for different elevations of foot placement and ensure that the foot can clear obstacles? I would think that there would have to be other parameters than the two easily visible ones to result in locomotion that is both efficient and capable. Is the entire skeleton fused? Might there be more familiar control systems within the main body mass?

I'm also still curious as to whether you've given any thought to pneumaticity in large Furahan organisms such as some of your rusps and in flying organisms, since I never got a reply on your origami post. Here's a quick overview of pneumaticity in sauropods in case you're not familiar with the term:
http://svpow.com/2007/11/03/tutorial-3-pneumaticity/

I realize that the largest rusps are considerably smaller than large sauropods, but they still have tremendous bodies. It also occurred to me that pneumaticity in winged animals could have implications for your series in ballonts. Even if heavier than air, a winged balloon might be able to achieve flight at very large sizes.

http://www.youtube.com/watch?v=UxPzodKQays

Sigmund Nastrazzurro said...

Andrew: That is a good point about the lateral bending resistance. What I was talking about was merely the material and its properties: as stipulated, it must be movable in an realistic manner in the fore-aft direction, but it ought not to allow much movement sideways.
However, the properties of the material do not exclude control of the limb in a lateral direction, In fact, you are quite right that such movements ought to be controlled. I would guess that, very similar to vertical mammal limbs, movement in a lateral direction are mostly controlled in very proximal joints.

As for pneumaticity, I am familiar with the term. The reason I had not answered was simply that your comment made me think; that, coupled with little time, made me forget. It happens; sorry. but yes! The apparently solid rusp body is much less solid than you would think. The bones might be the most pneumatic organs, but there are considerable 'volumes' of animal that are not really part of the body, but air instead. T

Evan Black said...

The old axiom once again holds true: a picture paints a thousand words. The bubbles-on-stilts are clear examples of the project's musculoskeletal idiosyncracies. While it shines a lot of light on the general physiological properties, I too wonder about lateral control of the legs on a specimen like this. Bending in unwanted directions is one thing, but I also wonder about the creatures simply tipping over. Is that translucent body supposed to be pneumatized to lower the center of gravity, or even lighter than air bladders to help the creature stay upright, leaving the legs free to provide propulsion instead of support.

The walkingmouth still confuses me. I don't know if it's a matter of scale or ecological niche or what, but I'm just not catching the spirit of the creature. Is it an insectivore? A piscivore? What is guiding its form and design?

Ronan said...

Fascinating design! A bow-and-string arrangement had never occurred to me before as a possible way of constructing a skeleton, but the idea is ingenious, difficulties with sideways flexion and torsion notwithstanding. The exposed musculature (and the exposed open loops it creates, which is a feature that, across clades, Earth life seems to avoid like the plague) is irking me, though. Is the musculature left exposed solely for the sake of illustration, do you know, or are these creatures truly intended to have gaping holes and loops in their legs? It seems like that would be immensely risky for the creatures, given how easily such loops could get caught or snagged on the beasties' surroundings.

Jan said...

I must say that I do not find this arrangement very realistic. The legs seems more as if skinned, those empty spaces would create some problems and without muscle antagonist the animals seem to have less control over the force they can apply.

But there is one style of movement where bow-and-string model is very useful and that is kangaroo-style hopping. I was always wondering, if this style is better than simple running in terms of efficiency, could it be used for even bigger and more advanced animals? It seems that for kangarooos start and slow movement is more problematic than for other runners...

puyamaster said...

Good! It looks that 'mouth unit' of the Walkingmouth has eyes on each side....

Sigmund Nastrazzurro said...

Evan: I too wondered about the bubblesonstilts tipping over, but have no information about lateral leg movement at all. All I was told is in the post.

Ronan and Jan: I think the open loops are designed to be there in the actual animal.

I wondered whether it would be possible to have the bone less bent in its 'normal' position; the muscles could then lie closer to the bone, and their momentum cold be increased by having their tendon running over a protuberance sticking out from the bone. The idea would stay the same but the bone and muscle would be closer together, doing away with the large open loops.

A 'kangaroo' with such legs would be strange to see: when it lands after a jump the shin would bend visibly under the weight, and when the animal pushes off the bone would straighten again, releasing the energy gained in landing.

Puyamaster: Yes. By the way, you asked recently about the 'Krakken' project. There is much information here: http://s1.zetaboards.com/Conceptual_Evolution/topic/552253/1/
I do not think the Cyberworld film can be found in its entirety anywhere. I do know that models made in France to help the animators can be seen here: http://www.chimeric.org/english/page61.html

Jan said...

I think that there is no need for the muscles to be closer to bones, the loops just could be hidden under the skin. But the animal would look less exotic, which is probably the reason for the loops in the first place.

Petr said...

the bubbles on stilts are very visually pleasing and interesting!

uncephalized said...

Hi SN. Been following your blog for some time and wanted to share some of my own sketches. These are literally photographs of my sketch pad so pardon the relatively poor quality. I just got a nice new drawing tablet though, so hopefully soon I will give a few of these creatures a little more life...

First, a few forms based on Terran ecology (but not from Earth; these particular examples are to be found on Eogea, with close relatives found on other Teranovan/Bessurian worlds).

http://vanvardo.com/wp-content/uploads/2014/02/ganderstud-small.jpg
http://vanvardo.com/wp-content/uploads/2014/02/river-lion-small.jpg


Then an "exo-clade", the tetrahedrids, indigenous (via a separate abiogenesis event) to Eogea's sister planet EG2:

http://vanvardo.com/wp-content/uploads/2014/02/primitive-tetrahedrid-small.jpg
http://vanvardo.com/wp-content/uploads/2014/02/squesque-small.jpg
http://vanvardo.com/wp-content/uploads/2014/02/reef-pudgie-small.jpg
http://vanvardo.com/wp-content/uploads/2014/02/trark-small.jpg

These are from a couple different fiction projects I'm working on.

Sigmund Nastrazzurro said...

Jan and Petr: you could indeed cover the loop with skin, but it would still be a large area. Whether that is a disadvantage depends on chances of getting it hurt, fluid or heat loss, etc. But they certainly are exotic and pleasing

Uncephalized: I very much liked your river lion; it has a nice 3D position and the right energetic looking pose for a otter-like animal. I also liked the pudgie, in part because the 'it does not always work' shows a sense of humour. I would like to see the pudgie in more 3D detail, but that may have to wit until you have learned to deal wit your tablet. I found it shockingly hard at first.

A final thing is that you might want to take a look at the speculative evolution forum, particularly the 'habitable zone' part. If you post your work there, you will get many more comments than here. The address is here: http://s1.zetaboards.com/Conceptual_Evolution/forum/236091/

Anonymous said...

Dixon should be writing books about these instead of the kiddy dinosaur books he's churning out nowadays.

Sigmund Nastrazzurro said...

Anonymous: I have not asked him but suspect that his preferences might differ from what he actually does. The market for children's dinosaur books is constantly renewing and nearly insatiable, whereas publishers seem to think there is no market for speculative biology at all. Perhaps they even see the lack of such books as evidence that there is no market for them...
If you make a living from this, you may have to choose dinosaur books.