3
$\begingroup$

I'm basically designing a quadrupedal digitigrade alien, which has evolved from a predominantly arboreal animal into a predator with more cursorial adaptations, capable of running fast, but still being able to climb well. It's 4 limbs possess 2 opposable digits and 2 middle digits used both for running and for climbing, having a structure that remotely resembles a zygodactyl bird's (that is, one opposing digit on each side, but these are not used for running). My original approach was for its front limbs to engage in a knuckle walking pose, especially in order to conserve its claws, but apparently that would make it unable to run fast, maybe due to low stability.

My second approach would be to have very flexible digits with joints capable of bending in an angle near 180 degrees, similar to the flexibility of the fingers from the images below (nemesis 2nd form, resident evil 3 remake), which technically would allow it to still be able to grab without staying in the way while running.

enter image description here

enter image description here

My question is: is it viable for my alien to have this kind of flexible digits in order to adapt well for both running and climbing? Are there better adaptations to allow for this kind of movement? Preferably I'd rather avoid the retractable feline claw path , since it doesn't seem as good for climbing as it is for running, and lacks the opposing digits.

Aditional info: it's sharp claws and front limb strength are its main tools for subduing and killing prey. It's world has earth like conditions with slightly denser gravity and its habitat is composed of large open plains with sudden cliff-like elevated regions spreaded across the region, which are the reason it still needs to be good at climbing (uses these as mating grounds).

$\endgroup$
  • $\begingroup$ From the image it seems like an awful lot of pressure on the fingers and thumb to support its weight while running. $\endgroup$ – RandySavage Apr 17 at 23:38
  • $\begingroup$ @RandySavage I agree, but it's precisely due to the amount of pressure that it's flexible nature becomes so easily visible, which is why I used it as a means of showing what I'd like it to be able to do . $\endgroup$ – ProjectApex Apr 17 at 23:53
  • $\begingroup$ I suppose if the majority of the weight was supported by the area of the palm that is touching the ground, I'm not sure if the thumb needs more muscle. I initially thought the fingers would get in the way of running but I could imagine a gait like a lizard with arms swinging out to the side. $\endgroup$ – RandySavage Apr 18 at 0:23
  • $\begingroup$ @Randy savage I would agree, if the game preferred to make it run like a mutant wolf or feline. But again were talking about a video-game bioweapon who ignores the mass conservation laws on a normal basis, so I won't complain on such a small thing. $\endgroup$ – ProjectApex Apr 18 at 1:12
  • 1
    $\begingroup$ I was meaning for your design, I didn't know how the new version of Nemesis moves. I am now thinking even if more weight is placed on the palms then your creature might need bigger pads at the fingers and thumb tips for grip and support. $\endgroup$ – RandySavage Apr 18 at 1:34
1
$\begingroup$

Talons(calcaneus bone) or tail.

The reason humans have a hard time running on their hands is not because we are afraid to break or precious nails but because of talons, if we had talons on our wrists like we have on our feet we'd be able to run on our hands without training.

For example the human arm has a better design for running, it's more flexible and there's no freakin' knee caps which means less chance of injury overall.... But well evolution is strange.

If your alien has a tail then it becomes even easier because it balances the limbs automatically.

Just take a look at the human foot, its basically a giant hand with a calcaneus bone for balance enter image description hereenter image description here

And it is obvious to say that human hands are perfect for climbing, actually people don't even need the entire hand to climb.... 1 month of bouldering and any person can learn how to climb using only their finger tips.

| improve this answer | |
$\endgroup$
  • 1
    $\begingroup$ The foot is also far far less flexible to withstand the forces of running and reduce the chances of over-extension or dislocation. And the large number of digitigrade mammals disproves your statement about the heel. the heel actually makes the limb worse at running by transmitting shock directly to the other joints. Also you are completely wrong about the patella, it has important functional benefits. $\endgroup$ – John Apr 18 at 3:56
0
$\begingroup$

If it can rotate its hand around completely, then it should be able to run on the back of its hand with its fingers kept safely curled into the palm

| improve this answer | |
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.