One thing to note here: this structure is actually a beautiful example of an important part of evolution: the re-use and adaptation of existing structures. These species’ ancestors had an external shell (think nautilus). But through evolution, they kept the skin cover permanently, and they were reduced to the current form.
Essentially, they converted an external shell into an endoskeleton. I think that’s exactly the kind of cool stuff we would like to have.
We can only implement so much cool stuff within the timeframe a stage’s development has though
You make a good point about CoM vs CoW. However, while I do think having an idea of Muscle vs Fat distribution would be useful, I would like to point out, Tigers are more muscular than Cheetahs, and Cheetahs run faster. So it is more complicated than either suggestion.
Good catch about Patagium. It is often not connected to digits or wrist. Some connect between limb and torso (with there digits, and sometime wrists, still free), some have it in the middle of an appendage, and certain lizards even bend out there ribs and have it between those.
I actually think @Deus’s idea about Digits being weakened makes more sense.
At least 2 dinosaurs, The scansoriopterygid dinosaurs Yi and Ambopteryx, are thought to have had both Feathers on there body and Bat-Like wings. So I agree.
Um, are you referring to this?
Only to a certain point, beyond it more muscles would lead to more strength but not necessarily speed.
You both have a good point here, speed is a more complex measure. Really, muscle power, limb shape (levers!) and simple stride length all come into it. So we’ll have to see how to reduce it into a manageable number of factors.
But I think limb muscle + shape versus overall creature mass might be a good start. (That tiger is of course in total a lot heavier than that cheetah, not just in the legs). The cheetah of course also has a different limb shape and a different (longer) stride (for many reasons).
I am amenable to digits on wings being overall weakened, but it can’t happen instantaneously by a fixed amount once a wing starts to develop. Otherwise there is a large fitness loss for little fitness gain. That does not make evolutionary sense in my opinion.
This part at least seems an easy conversion of the existing concept, allowing you to select parts other than the digits as endpoint.
Not your comment specifically, but yes, that general concept. Floating hydrogen balloon lifeforms are a fairly common speculative evolution feature.
To determine what sort of characteristics a limb shape at a certain size has, will simulations of it be run in some kind of a realistic environment to decide what statistic will it come with?
And I assume lower difficulties would have more leeway for less than optimal limb and body designs?
Again, difficulty =/= realism.
So there will be eventually an option to adjust the stringency of body and limb designs? How much will Players be able to adjust such stringency, if added? A Player might end up with too crazy organisms…Like what happened in the ancient past with real life…Hmmm… 
I mean, maybe limb statistics will be determined some other ways that is less “customizable”…
While emphasising that design is not final here, I would suggest not putting your hopes higher than things like “mass” and “streamline” (like mentioned in the document), and if necessary things like “length” and “angle”. Those numbers would then have direct gameplay effects, probably.
Very likely not. Auto-evo balance would be extremely messed up with that.
Much more likely that lower difficulties would make it easy enough to survive even if your design is bad. (which is mostly how current difficulty works.
Will flying creatures be checked for their streamlineness across their whole body?
I assume the amount of streamlining would be more severe for underwater creatures due to greater density of fluids versus gases. Make me wonder if Players could evolve Flish-like creatures…
@DevonHalstonDreadle
I generally like your list of Terrain Materials, however, I noticed that you only have Sandstone in Tide Pools. Sandstone forms in a variety of environments, including Deepwater Deposits.
I wonder what @fralegend015 thinks about the list of Terrain Materials, considering fralegend015 works as a Geologist.
Wait, where did you find that info?
I believe both of these examples are mentioned in the linked document. For the near future, that’s probably as close to “the plan” as you’re going to get.
Would an even greater density there be for mud-dwelling creatures?
This sounds like a very good idea. While I do not play that way, making a highly toxic build being able to kill an engulfed organism as an effective strategy would definitely be beneficial for the Player base. Could it also work by having the engulfed toxic damage effect be based on a being above certain toxin amount threshold, and factoring in amount and type of digestive enzymes (if this isn’t used already)?
Could some organisms use being engulfed/eaten as a way to become parasitic?