So, birds aren't exactly the most flexible creatures. Sure, they got their neck, but their ribcage is fused and solid.

This is true for all flying creatures, including dragons, as the ribcage needs to withstand the stresses of producing wing strokes that lift the creature.

Oddly enough, giant pterosaurs had very short, but rather wide, torsos around 60 cm in length. Sure, their digestive system was very minimal. We can assume a similarly shaped ribcage for our dragons.

Other dragon stats:

Neck+head length: 2 meters
Height at shoulders: 183 centimeters
Body length: around 2-2.5 meters
Tail length: ???
Max weight: 500 kg

Dragons have six limbs but mostly use their wings in launching (quad launch) and landing. The forelegs are placed in front of the wings and connect to a short extension of the ribcage. This extension can be more flexible since it doesn't have to withstand the stresses that anchored flight muscles exert.

Considering that I wanted my dragons' kinesiology to have more in common with Toothless and felines than horses, it's time for me to fall into despair while you try to sort things out.

According to the 3.5e Draconomicon,

A dragon on the ground moves like a cat, and can be just as graceful (though the bigger dragons tend to lumber along). When it’s not in a hurry, a dragon walks by moving two legs at a time. The dragon lifts one forefoot and the hindfoot on the opposite side. Like a cat, with each step the dragon places its hind foot in the place where the corresponding forefoot was.

As it strides along, a dragon keeps its wings loosely furled at its side. If it is feeling lazy, it lets its tail drag behind. Usually, however, a dragon holds its tail off the ground, and the tail slowly moves from side to side in time with the dragon’s gait. The motion helps the dragon keep its balance. The tail sometimes brushes the ground, but only briefly and usually well to the left or right of the dragon’s body.

A running dragon can easily outpace the finest horse. It uses a galloping motion, moving both front legs together, followed by both back legs. The wings stay furled, but the dragon spreads them occasionally to maintain balance. The tail is held high.

Dragons can also swim (in a similar style to water monitors) and burrow, suggesting great flexibility all around and the ability to crawl through (for them) fairly small spaces, which is pretty useful.

So, let's assume I want my dragons to have these styles of movement (cat-like walking, running, tail-assisted swimming, and burrowing like a fox). These require the legs to have much better flexibility.

The only real change I will throw in the mix was that while dragons can still outpace horses for a short time, they have abysmal stamina (since most of their muscle fibers are fast glycolytic). Muscles that help maintain your posture are the less-powerful, slow oxidative type.

Around 25-20% of the dragon's total weight has to be their flight muscles, as per Marden's observations. This leaves the Quetzalcoatlus northropi with 187 kg and our dragons 375 kg to work with, worst-case scenario.

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I established beforehand that dragons can efficiently produce CNT and use it to reinforce their collagen-based tissues, so their tendons and bones can be stronger in their own field.

How can I give my dragons' limbs similar flexibility to felines' without compromising their ability to run or walk relatively quickly?

Yes, dragons are genetically engineered creatures in my story, in case you want to take an unconventional route.

Yes, reptiles also have their own form of locomotion, blah blah, have this galloping crocodile as a reward!

bonk A burrowing brass dragon. Listen, this is a x4.0 upscaling, don't expect it to be perfect.

  • 6
    $\begingroup$ That was a... lengthy read... and most of it didn't seem relevant. I've tried to think of how to express my concern a couple of times, with no success. What are you asking? To physiologically justify a creature that flies, burrows, and is agile? Are you asking us to design the entire physiology of your dragon (because more than rib cages goes into all that)? Do you have a specific question, because that seems outside the scope of the site. What's the problem you're trying to solve? $\endgroup$
    – JBH
    Commented Aug 26, 2020 at 1:40
  • 1
    $\begingroup$ @JBH I'm searching for a justification for the increased range of motion in my dragons' fore and hind legs, compared to horses. Mostly because I wanted my dragons to be able to crawl, pretty useful in many scenarios. $\endgroup$ Commented Aug 26, 2020 at 1:46
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    $\begingroup$ Compared to horses? Where'd that come from? The question only mentions that dragons can outpace a horse for a while but doesn't have their stamina. If horses are the comparison, you need to edit the question. Frankly, edit out 80% of the question then specifically ask, "how could I change the traditional physiology of a dragon to increase it's leg range of motion to exceed that of a horse." Be prepared for the results, because lizard legs have much more range of motion than horse's legs. $\endgroup$
    – JBH
    Commented Aug 26, 2020 at 1:53
  • $\begingroup$ @JBH I know, but... $\endgroup$ Commented Aug 26, 2020 at 2:18
  • $\begingroup$ galloping crocodile ! i dont quite get the question, but sounds like you want a leg/limb that can climb and crawling? regarding climbing wont having strong claw or strong flexible finger help? or maybe use the gecko paw way for that? i dont get what you mean or want with the crawling, but maybe they can move their belly like snake/some lizard do? to help increase the crawling. $\endgroup$
    – Li Jun
    Commented Aug 26, 2020 at 4:51

1 Answer 1


Unfused bones

This is the most standout by the cheetah, because a cheetah's skeletal is unique in the sense that very few of its bones are fused or connected together. A human has problems rotating their shoulder because the way that the ball-and-socket joint works - a cheetah, on the other hand, can more or less move the entire shoulder, joint and all, while running, giving it that supreme flexibility. Of course, there are some drawback, namely that you sacrifice structural integrity for that kind of flexibility - there's a reason why cheetahs do not make good pack animals. If you unfused the dragon's bones and relied on muscle structure to help keep everything in place, that would go a long way towards increase flexibility. Of course, it'll make them bend like a pretzel in sufficiently strong winds, but that's how trade-offs work.

  • $\begingroup$ How do you relate anatomy to pack hunting? Lions are co-operative hunters yet tigers aren't. However skeletally these species are almost identical. $\endgroup$ Commented Aug 27, 2020 at 23:06
  • $\begingroup$ @chasly-reinstateMonica I'm no expert, but I would say that pack hunting is more of a derivative of social structure than anatomical structure; and that a large part of it is based off the prey the species in question hunts. $\endgroup$
    – Halfthawed
    Commented Aug 28, 2020 at 0:10
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    $\begingroup$ @chasly-reinstateMonica I think what they were saying was that cheetahs would make poor beasts of burden. $\endgroup$ Commented Aug 28, 2020 at 1:57
  • $\begingroup$ @Mephistopheles - Ah thank you. That makes sense. $\endgroup$ Commented Aug 28, 2020 at 10:16

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