The Book is announced!

The Book is announced! 

Yes, I do mean my long-awaited book about Furahan wildlife; for me, this is not just a book, but 'The Book'. 

Before anyone becomes overexcited, let me start by saying that it is not available yet; you will probably have to wait until November to get your copy! 

The publishing process is advancing nicely and has now reached the stage where The Book is announced to booksellers. This means you can search for it on booksellers' websites, but it will not be mentioned in every country yet. Because Crowood Press, the publisher, is in the UK, UK sellers and sites are first to mention it. I recommend 'speculative biology furaha' as a search term to find it quickly. 

Mind you, the official price has not been settled yet, in spite of you may see! 

Here are the cover and accompanying text, with thanks to Dougal for the praise! 

 

Click to enlarge; copyright Gert van Dijk

"On the planet Furaha, Gert van Dijk creates a biosphere on a new world along with its solar system. Evolution on Furaha found solutions to life’s problems that remained unused on Earth. There are in-depth accounts of habitats where marshland mixotrophs use bioluminescence to catch animals, where four-sided radial cloakfishes swim in tropical waters and where tetrapters flitter through the air, using radial flight. With over 180 stunning illustrations, this is a book that all fans of science fiction, biology and science will enjoy, and that will inspire artists to think beyond the limitations of our own planet. 

 'Major works on speculative biology are rare but Furaha is a welcome addition to the genre and gives a well-considered account of life on another planet, along with stunning illustrations. This is a must-read book, which I heartily recommend.’ ~ Dougal Dixon The father of speculative zoology"

Why Furaha is like Earth

Furaha is very much like Earth. The planet dies in fact differ from Earth in all aspects, but the departures are limited, so gravity, the temperature range and atmospheric composition are all close to those of Earth. 

I did not choose this similarity because I wanted the planet to be suitable for humans. The choice to add humans was made much later, and humans are simply there to add human interest and humour; few things are funnier that human behaviour, I think, even if you have to ignore stupidity and greed. The earlier choice to make the planet Earth-like did have a large effect on the human presence, as it meant that humans could mingle with the animals, fall into pools and could be stung, bitten and spat at by local spidrids, wadudu and kermitoids. In short, they could live on the planet, rather than be neutral observers isolated by space suits. 

 A big part of the attraction of speculative biology is that the animals, plants and other thingies are unearthly. If a high degree of unearthliness or alienness is the aim, shouldn't the environment itself be unearthly? Wouldn't an extremely low or high gravity, or temperatures hot enough to melt lead or cold enough to allow methane lakes evoke such alienness? I think the answer to that is 'yes'. But I chose otherwise. 

Mind you, extreme environments pose problems. One would be that there should a biochemistry that works in environments in which Earth creatures would freeze solid or burn to a crisp in seconds. But the purpose of The Book was to show life forms through paintings, and you do not see biochemistry on a painting. Well, indirectly you do, of course; if life forms need large areas for photosynthesis, that fact tells you something about photosynthetic efficiency; likewise, the presence of insulator coverings tells you something about metabolic temperature. But in such cases you only have to accepts that some type of biochemistry is behind what you see; you do not need details. 

Gravity wasn't the problem either, because gravity translates to mechanical stress, and designing appropriate mechanical adaptations is quite doable and can be represented well in paintings. 

Reflections off Titan. Click to enlarge. From here

The real problem is painting the mundane aspects of a creature's environment. Take a methane lake as on Titan. What colour is it? We know it is reflective, but is it transparent too? Do the degrees of reflection and of transparency depend on the angle of vision? I love painting water surfaces, so these things matter to me. On Earth, we are so used to all aspects of water, variable as they are, that I could show you a brownish flat surface with some reflexions on it and you would equate that with muddy water without even thinking about it. Staying with water, we are used to interpret wave amplitude ands wavelength, and immediately know whether a scene shows a stormy sea or ripples in a calm pond. Well, Titan's sease appear to be extraordinarily smooth (Wye et al 2009). There are waves on Titan, about 20 cm high for a wavelength of 4 meters (Lorenz and Hayes 2012). But even with that knowledge I would have to know much more about viscosity, foam, etc. before I could paint them. In fact, it would be nearly impossible to turn such data into any approximation of what the surface looks like; to do that, you need to see it. 

Use of atmospheric depth by Caspar David Friedrich, who really knew what he was doing

 

Rather less competent use of atmosperic depth in an old Furaha painting

Perhaps some planetary scientists have good ideas of what methane lakes really look like, but I do not. I guess painters have to see them before they can see them, and without close-up videos we have no idea. I could go on like this about rocks, soil and sand: does the wind produce ripples in the sand on the beach? The atmosphere is interesting too: are there clouds? What is their shape and colour? Any landscape teaching course class will introduce 'atmospheric (or aerial) depth'. That means that, if you wish to paint hills or mountains as if they are far away, you should make the colours pale, bluish, with little contrast and detail (at sunrise or sunset colours can become reddish rather then bluish). To which extent does aerial perspective apply to Titan? The physical mechanism behind it is Rayleigh scattering, and that probably works in the same way regardless of the composition of the atmosphere, but the effect may still be affected by the composition of the atmosphere. Some exoplanets may have blue skies, like Earth. This means it is reasonable to turn the colours of an alien atmosphere bluish near the horizon. But the sky right above you need not be blue itself, as we know from Mars, so the colour of the sky itself might be different. And that does not take the colour of the local sun into consideration, which might, for instance, cast such a red glow over the scenery that we would find it difficult to tell noon from sunset. 

The simple reason Furaha is so like Earth is that that choice allowed me to paint backgrounds and many details of Furahan landscapes without endless study and much uncertainty on my end. I feel that the uncertainty would also affect the viewing of the paintings. When I paint something that looks like a smooth reflective surface with some undulations, you might think it is viscous oil or even mercury, rather than what should show up as a nice refreshing Titan lake. It is much more helpful to fall back on people's expectations: when I paint a nice transparent aquamarine surface with the sun glinting off it, and if I manage to do that really well (which is not a given!) I would like people to wish they could jump into that nice tropical water. 

They shouldn't do that, of course, because of the sawjaws, but you get the drift. 

 

References

Lorenz RD, Hayes AG. The growth of wind-waves in Titan's hydrocarbon seas. Icarus 2012,  219: 468–475

Wye, L. C., H. A. Zebker, and R. D. Lorenz (2009), Smoothness of Titan’s Ontario Lacus: Constraints from Cassini RADAR specular reflection data, Geophys. Res. Lett., 36, L16201, doi:10.1029/2009GL039588.

 

Forming scientific names for speculative creatures

Almost all species in The Book have names. Some that only function as background material in the paintings remain nameless, but some other of such extras did receive a name, because I like naming them: it add a layer to their fictional existence. 

As my native language is Dutch, you might think that all species start with Dutch names, but that is not the case. I use both Dutch and English professionally and know better than to translate my own texts. You get a much better result if you write a text from scratch in the intended language, because otherwise the other language always gets in the way. The names of Furahan creatures are usually either inspired by existing names or by sound associations. For instance, an animal called a 'siphizilly' evokes a different feeling than a 'grackror'. 

The people populating the Institute of Furahan Biology were supposed to be linguistically diverse and would use words from various languages. For instance, there is a clade of tetrapters with large and colourful wings called the 'Farfalloidea'. Italian speakers will immediately recognise the Italian word for butterfly: 'farfalla'. 

Named creatures also receive a formal scientific name. That is the binomen, with a genus part, starting with a capital letter and a species part, starting with a lowercase letter. The official rules even recommend that you should never begin a sentence with a species name, because that will force a capital letter on the species name (recommendation 28A). Not that I really understand why that amounts to a capital offence (sorry for that one), but never mind. 

For those who like to name animals for themselves but do not like to wade through the entire zoological as well as botanic nomenclature codes (the rules are not exactly the same), I will provide a few simple rules here, focusing on zoological names. 

Choose a noun for the genus name, such as 'Bestia', meaning 'animal' or 'beast'. Use the singular form, not the plural, and make a note of the gender of the word. 'Bestia' is a feminine word. Existing Latin and Greek words always have a gender that you can look up easily in a dictionary; the gender will be masculine, feminine or neuter. If you make up your own word, you must choose a gender. An easy way to do so is to Latinise the word by choosing from three endings that evoke the gender: '-us' evokes a masculine ending, '-a' feminine one, and '-um' a neuter one. It is not compulsory to add such an ending though. Mind you, the Code insists that you specify a gender in all cases. If you choose an adjective for the species name you will have to use the form of the adjective of the appropriate gender. 

Then, choose a species name. You have basically three choices. 

• You can use a noun again; for example 'Bestia bestia' or 'Bestia calo' ('Calo' is a masculine word denoting a 'type of awkwardness'). The gender of the second noun does not have to be the same as that of the genus noun. Some people string some nouns together to form a name, such as 'Bestiacalo'; in such strings the gender of the last noun wins, so the word 'Bestiacalo' is regarded masculine. 
• You can use an adjective; it must match the gender of the noun. Say you wish to use the Latin word for 'pretty'; the dictionary will provide the masculine form, 'pulcher', and the feminine form of 'pulchra'. If you change the '-a' to '-um' you get the neutral form. Using the 'bestia' example again, you could form 'Bestia pulchra' (feminine), or 'Bestiacalo pulcher' (masculine). 
• You can also use a genitive of a noun, often done to name a species after someone. If you wish to honour someone called 'Rodger', you ought to turn that name into a Latin form first. For men you add '-us' or '-ius', resulting in the genitive endings '-i' or 'ii'.  The genitive thus becomes 'rodgeri' or 'rodgerii' for men. For women, say 'Violet', you also first turn the name into a Latin version by adding '-a' with the genitive '-ae'. So you get 'violeta 'or 'violetta'. To make life simple, '-i' works for neuter genitives too. 

I use freely available Lexilogos dictionaries for Latin and classical Greek and rummage around, taking notes, until I find a combination of words I like. I am old-fashioned so I do not mix Latin and Greek. Using Greek is more complex than Latin, because you have to be able to read the alphabet of classical Greek and how to transliterate Greek words to Latin ones. Mind you, there are interesting words there, such as the following I found for 'beast': 'thremma', 'therion', and 'knodalon'. 

That's basically it! For me, the fun part is finding names with an appropriate meaning as well as a nice sound and cadence. Here are some examples of animal names that did not all make it all the way to The Book. Syllables in bold tape carry pronunciation stress, although this has always been a weak spot for me so I cannot guarantee accuracy. 

Click to enlarge; copyright Gert van Dijk.

• Tonitrus onerosus; a very large hexapod. The name means 'weighty thunder'. This anem was used for the large animals on a now no longer useful painting showing the 'Tonitrus onerosus', with the common name of 'Gromachin' (in this instance French provided the inspriration) 
  
• Ira tarda: 'slow anger' 
• Ferpilum perfidum; 'Ferre' is the verb 'to carry'; a 'pilum' is a javelin, so ferpilum means 'javelin carrier'. 'Perfide' is French for treacherous. 
• Brutum rutrum ; brutum: dull, stupid, insensible, unreasonable. A rutrum is a shovel. 

Pronunciation is tricky. Many people just apply the spelling rules of their native language to scientific names, but the result may well be unintelligible to others, and the whole point of scientific names is that people over the entire world can use them. English is particularly bothersome in this respect, probably because of the 'Great Vowel Shift'. Sounds of English vowels do not correspond to those of other European languages. If you pronounce the word 'ira' (anger) as 'eye-rah', people for whom the letter 'i' always means an short or long 'ee' sound, may not understand you. I personally stick to the pronunciation rules for Latin I learned a long time ago. For example, these rules include always pronouncing 'c' as 'k', never as 's'. 

Complicated, isn't it? But do not worry too much. Speculative biology is for fun, and we shouldn't worry too muuch or get overexcited about how to pronounce made-up names of made-up life forms in a dead language.

Keeping on your toes (Frustrating Feet III)

 My last post was placed here on 16 December, and it is already almost March. The reason for that delay is that I had to get The Book ready for the publisher. And I did! The files have now all been sent off, neatly categorised by chapter and number. My wife and I proofread the text of over 60,000 words once more. I also went over all full-page illustrations again, as the page format was broader than I had originally used (there will probably be close to 200 illustrations in total). Luckily, digital paintings allows many ways to alter illustrations, and I only had to paint new parts of paintings a few times.

Right! Back to posting. Feet again this time. Let’s focus on toes.  

Why have toes at all? As discussed in the first post on feet, some animals get away without any toes at all (crabs) and others have just one toe per foot (horses). Feet, rather obviously, contact the ground. For small animals ‘contact’ may primarily mean the ability to actively adhere to the substrate, also discussed in the first foot post. For large walking animals, gravity will ensure that the contact surface is pressed against the ground.

That contact surface can be relatively small and hard, such as a hoof, and such small contact surfaces work best when the substrate is hard, so the foot will not sink into it. In contrast, the contact surface will need to be large if there is a risk of sinking into soft soil. There are two ways to enlarge the surface area.

Click to enlarge: source here

‘Elephant feet’
The first variant is a foot with embedded toes, ensheathed to form a sort of club foot ending in one large flat round surface, such as the soles of elephant or sauropod feet. In elephant and sauropod feet the toes are bundled up to form a kind of cone, broad side down. Such a structure is useful to spread weight through the toes across the shared sole.

T.rex foot; click to enlarge; source here

‘Bird feet’
The other variant consists of long independently mobile toes, such as ostriches and theropods have (I know, birds are dinosaurs). I will approach the question of whether independent toes are useful for two circumstances: dealing with uneven terrain and walking.

Which variant is best under which circumstances is not something I have been able to find in the literature, so, as always, students of speculative biomechanics find themselves on an insecure footing (sorry for that one). As an aside, perhaps courses on biomechanics should use speculative biology as a teaching tool: it forces students to ask questions that normal biology, dealing with observable facts, regards as givens.

Conforming to uneven ground; Click to enlarge; copyright Gert van Dijk

Dealing with uneven terrain
If that elephant foot with a large continuous foot surface is stiff and does not deform easily, placing one side of the foot on an elevation such as a stone will create a large bending moment. That can be solved by providing the ankle joint with some leeway to turn in all directions: the foot will rotate a bit relative to the leg until both sides of the foot will contact the ground. Mind you, that ankle motion must be tightly controlled, or else the ankle joint may move too far and is hurt (that's how you sprain an ankle).

In variant two, with independently movable toes, the ankle joint does not have to do anything as the solution then lies in the toes themselves. If such a foot is placed on uneven terrain, each toe can move until it contacts the ground. In reality, you can have a combination of the two designs

The two variants, one with big round feet and one with splayed independent toes, seem to be linked to lifestyle: sauropods, with big plodding feet, were immense, slow, and herbivorous while theropods were smaller (still large!), fast, and carnivorous. The dinosaur example has the advantage that the two groups have a shared ancestry, so the answer cannot lie in a different starting point. There must be a functional reason, and that is why I summed up size, speed and feeding method. The feeding method is probably not crucial, but lifestyle is, in the sense that an agile animal must have legs and feet to allow agility. Agility hare can be defined as meaning not only speed, but also the ability to turn, accelerate, absorb hard landings, get a grip, etc. I think that independent toes provide more agility than toes that are encased in a common sheath. My reason to think so is that animals with large round feet also had vertical leg bones, while those with independent toes tend to have leg bones that are slanted with respect to the vertical. Such ‘crouching’ postures require much energy just to stand still but allow jumping and hard landings.     

The image above overlays an elephant with T. rex at the same scale. Notice how the legs of T. rex are slanted while the elephant has vertical legs.     

Additional toe propulsion; click to enlarge; copyright Gert van Dijk

Walking
Elephants and brontosaurs on one side, and ostriches and T. rex on the other side. Both types of animals walk well, so one is not necessarily superior to the other. But we can speculate about consequences of foot designs.

There is probably one more factor of interest here, one that has to do with the direction of toes relative to the direction of walking. Toes usually point forward, or a bit to the side as well as forward. Is that a given? On Earth, very few animals have toes that point backwards. Some walking birds, such as roadrunners, have backwards toes, but you can argue that these legs are there only because they fit the Bauplan of animals that have to grasp branches or need to hold on to tree trunks, for which backwards-pointing toes are useful.  

A good reason to have forward-pointing toes is that they contribute to walking, by moving backwards relative to the ankle. The main propulsive force of the leg of an ostrich or a T-rex must come from movement in the hip, knee and ankle joints. But moving the toes backwards will still add force. The situation is similar to throwing a tennis ball: you can grip it in your fist but also with the tips of your fingers. To throw it far, the main acceleration will come from simultaneous extension of the shoulder, elbow and wrist joints, but if you hold the ball with your fingers, straightening your fingers will add a bit of acceleration. Not much, but worthwhile.

The image above aims to show that: the blue triangle shows where the heel/ankle touches the ground, and the red triangle where the tip of the toe touches the ground. By rotating the toe backwards the animal effectively gains that additional distance each step.  

The toes of T-rex probably also added a bit of acceleration by moving back in unison with the other leg joints. In contrast, the toes of elephants and brontosaurs probably hardly moved at all compared to their ankle joints. Does that put these clubfooted animals at a speed disadvantage? Yes, it does, but that toe assembly is part of a large set of traits that together illustrate that the animal is designed for weight carrying at the price of agility.

In summary, independently movable toes offer more agility and add propulsive force, which is why they may be tied to a more active lifestyle.

Barlowe's rayback; click to enlarge; copyright W Barlowe

Consequences for speculative biology
You probably know Barlowe's Expedition book. I always admired his paintings skills, but at the same time I also always felt that he often gave too much weight to 'alienness' , disregarding biological likelihood. In the past, I discussed why I though a planet filled with blind animals would be very unlikely (Here; the short answer is that vision seems to evolve very readily). Something I hadn't mentioned yet is that I always felt it odd that his very large agile bipeds had feet like those of elephants. I had an inkling that such feet did not fit such a lifestyle. I still cannot prove that, but at least I can now provide some reasoning rather than just a feeling.

Rusp toes; clich to enlarge; copyright Gert van Dijk

A second consequence is how toes should be placed on alien feet. As you may know, Furahan hexapods have jointed legs with three large segments and a few smaller segments at he end. There are there to provide that extra acceleration in running animals.  You will also find that rusps have two toes, or rather nails, at the side of their feet. These do not help with acceleration; rusps are fairly slow and do not benefit from a little bit of additional acceleration. As they have many feet, the surface of each does not have to be large. The bottom of the feet amounts to a horizontal strip, with nails digging in at either end. Rusps like a solid grip!        

From erect dinosaurs to pivoting fly feet (Frustrating feet 2)

This post is long, fairly complicated and rambles along a bit, so do not say I did not warn you. We are so used to seeing big mammals that most ‘alien’ legs in drawings and films are just mammal legs. One thing you will find in many books is that a key feature of mammal locomotion is that the legs are 'erect'. 

 

Click to enlarge. From Box 4.3 in: Fastovsky & Weishampel. Dinosurs A concise natural history. Fourth Edition Cambridge University Press 2021

 

The image above shows such a scheme, making the point that dinosaurs legs are as erect as mammal legs, using a human as an example. I have always felt that the legs of the dinosaur in the picture are not really 'erect', while the human's leg both are less erect than they usually are in a standing human. 

Click to enlarge; copyright Gert van Dijk

Let's explore this further. Above, you see the species Disniformis inexpectus and on the left its cousin, D. expectus. The elbows and knees of D. inexpectus stick out sideways, while those of D. expectus do not. Which animal stands in the most energy-efficient way, and which is the most 'erect'?

 <pause to think>

Many readers may feel that D. expectus wins on both accounts. But have a closer look: in both animals the feet are placed precisely underneath the hips, and the leg segments are tilted in opposite directions as you move down. Because the joints are angled, energy has to be spent to keep these joints from bending further under the influence of gravity. How much energy depends on the angle of the joints and how far these joints are situated from the vertical line connecting hips and feet. Guess what: the legs and joints angles are exactly the same. The legs were just rotated, except for the feet, so exactly the same amount of energy is needed to keep the joints stable.

Personally, I would call a leg fully 'erect' only if the segments are all vertical, as they largely are in standing elephants (and standing people!). If all segments are fully erect, the feet must end up directly underneath the hips. In the dinosaurs and both species of Disniformis, the feet are also placed directly underneath the hips, and it seems some authors use the word 'erect' to mean only that aspect. The opposite of 'feet underneath hips' (FUH) must be 'feet away from hips' (FAFH). If the feet are placed well to the side of the animal, you get a sprawling stance, like salamanders and insects use.         

Perhaps you feel that all this changes when the species start to walk, and then we will see that D. inexpectus can only plod along while D. expectus trots elegantly out of sight. Not so! The legs of both species can extend to the same length and the joints move through the same arcs. This means that  elbows and knees can be kept close to the centre of the animal regardless of whether they deviate to the inside, outside, back or front.

 

Click to enlarge; copyright Gert van Dijk

Still, D. expectus will have a gait advantage in that its joints can be designed much simpler than in D. inexpectus. The dinosaur drawing and the reworked D. expectus above show simple hinge joints that allow the legs to move only in a fore-and-aft direction. That save energy; nice, right?

It would be nice if animals were like trains, only moving along predefined linear tracks. But they also need to turn and to step sideways and do other things beside walking in a straight line. An animal must be able to move its feet fore and aft, but also to the side, and must also be able to turn toes in or out. This requires rotation along all three axes. You can be creative and appoint different movements to different joints, but iff you wish to obtain the largest reach for the foot, you should give the hip joint the most freedom. That is probably the reason mammal hips have ball joints (and dinosaur hips too, as far as I know). My guess is that the most proximal joints (hips/shoulders) in alien animals will also have three axes of rotation. Mind you, the three axes do not have to be used to the same degree in daily life (fore-aft movements will see more use than toe in/out movement).

The ankle joint should allow the foot to adapt to uneven ground, so the joint must allow a toe up/down rotation and also a thumb up/down rotation. That is two axes already; we will get back to the third axis. This leaves joints in between, and these need only have one direction of rotation, like mammal knees (that need not be universal though and is probably something for another post).

 

Click to enlarge; copyright Gert van Dijk

We are now getting to something that has vexed me for years. Above is an image from a post from 2010, showing D. salamandris. This is what I wrote at the time: "To get a movement suitable for walking, its foot should move in a straight line from front to aft … But ensuring that the foot always points forwards also requires that there is a way to rotate some of the bones around a longitudinal axis."

It is the need for that third rotational movement in animals with FAFH ('sprawling') legs that vexes me. Humans are very good at this movement, called pronation and supination (if you hold your arm in front of you, turning the palm down is pronation and turning it up is supination). But I couldn’t find good discussions on this type of movement in the prototypical sprawlers: arthropods. If readers know about such studies, please let me know.

I looked at some internet videos of walking insects to see whether their feet remained fixed to the surface while the leg rotated; if so, these insects had pro- and supination. I would expect the tarsus to allow that movement, even though the text I found previously said that the tarsus only allowed flexion and extension. If the foot would rotate along with the leg, it would pivot over the ground, something hardly compatible with a firm grip.

There weren't that many videos that allowed such close scrutiny, but here is one, showing a fly walking across glass. The foot stays in largely the same position and does not rotate along with the leg. To allow it to that while the hip is moving forward, something has to 'bend'. The tarsus indeed seems to bend a bit, but not much. In fact, the tarsus keeps on pointing in the same direction all the time. 

 

Click to enlarge; copyright Gert van Dijk

I thought of a possible explanation, and it involves a different kind of hip movement. Above are two spidrids. The first has a typical vertical axis of rotation through the hip; that's a normal spidrid. The rest of the leg lies in a plane, and the movement is shown by two 'ghost legs' (this is typically how crabs move). The second image has another hip, with the axis horizontal. The animal can still reach fore and aft, but the results looks different.

 

Here is what the differences amount in an animated view: first a typical spidrid movement with a vertical axis. The gray structures indicate the planes in which the legs move.

 

And now a Neospidrid with a horizontal axis (the model caters for intermediate angles too).

An thay means we can get back to flies; in a textbook of arthropod anatomy (Manton 1977) I found indications that insects hips have an added 'rocking' movement that would indeed allow some rotation around a horizontal axis. But there's a rub. With such an axis, you still need pro- and supination to keep the insect's 'palm' against the surface. I still do not know how insects solve the need for this longitudinal foot movements. Crabs are probably easier, as they have no feet in the common sense, so they can just pivot on the tips of their legs. 

I confess that designing alien animals is sometimes easier than studying Earth animals. In particular when it comes to feet!