A scientific analysis of Dragons and other large fantastical flying reptiles

[Redfrogcrab]

Howdy yall
Using the powers of evolutionary biology and general biology, I will provide an analysis of dragons (and variants) and how they could realistically evolve within this thread, suggestions and comments are greatly appreciated

First up: Standard dragons

The big problem anatomically (besides fire breathing) is the wings and where they're placed on the body.
In yee classic mid-evil dragons, the wings are placed directly on the back, typically in evolution, vertebrates that are capable of powered flight adapt their forelimbs into wing structures, why?
for one, musculature, limbs need musculature, terrestrial legs, and arms, need some musculature, but wings need LOTS of it. Wings generate thrust by flapping, and thrust, paired with lift, lets you fly in the sky, the powerful muscles required for this also need anchor points, usually bones like a pelvis or shoulder blade, thus back wings are not possible, hell, that's not how evolution works.
Typically, tetrapods don't just add new limbs, all tetrapods (p.s. tetrapods are all reptiles, birds, amphibians, and mammals) have (or, at least have vestigial structures of) 4 distinct limbs.
Therefore, either
A. classic Dragons are not true reptiles (or even true tetrapods) but are instead a distinct class of terrestrial vertebrates (that I will dub Hexapoda) that convergently evolved a lot of tetrapod features (limbs, lungs, and specifically for dragons, scaly skin and amniotic eggs) but have an extra pair of limbs. It's my personal theory that the wings of classic dragons are the middle pair of limbs that have evolved to be wings.
B. somehow, some way, a group of reptiles just randomly got an extra set of limbs
dragons would have to be small and lightweight too, more mass means more thrust, and more thrust means more energy is used. I'd say the largest a dragon could get is about the size of a giraffe (as that's about the size of Quetzaquatlus, the largest flying animal ever, got)
In short, classical dragons would probably not be closely related to any tetrapod species, and be their own class of terrestrial vertebrates with 6 limbs instead of 4

Secondary problem with classic dragons: Fire breathing
This is actually something I could see naturally developing, kinda. Who said that the fire breathing had to be with an actual fire? certain ant species and a species of beetle have developed ways to spit out acidic compounds that sting like hell, and guess what vertebrates have in their stomachs, that's right, Highly acidic liquids. I believe that the dragon's "fire breath" is actually them spitting out stomach acid on prey, originally as a way to ease digestion, now just straight up spitting acid on prey (and mid-evil villages) to both kill and pre-digest (kinda like some spider species).

 

[pmmg]

All speculation, of course.

One assumes the weight of dragon precludes flying without great effort, but internal heat and gasses does add buoyancy, and dragon musculature is not like your common human or orc, and certainly not elf. Much stronger and powerful stuff goes into dragon flesh. That, and supernatural powers often assist in the fire production.

 

[Redfrogcrab]

All speculation, of course.

One assumes the weight of dragon precludes flying without great effort, but internal heat and gasses does add buoyancy, and dragon musculature is not like your common human or orc, and certainly not elf. Much stronger and powerful stuff goes into dragon flesh. That, and supernatural powers often assist in the fire production.

In biology, muscle is muscle, the dragons might have denser muscles, but it's still made from the same stuff all animal muscle is made from, the problem is where does that muscle attach too and how the wings develop.

We're also assuming magic does not exsist to assist in dragon anatomy, because hand-waving it as magic is boring and a cop-out

 

[pmmg]

There you go again using words like 'science' and 'biology' to explain the mythical.

 

[Redfrogcrab]

Because it's damn fun to figure out how fictional organisms could work and evolve using irl science

 

[pmmg]

Yes, but... some of these creatures are so attached to mythical and supernatural origins, they could not be separated. Could a devil have hell fire without hell?

And I did give two plausible reasons. Dragon have hot gas which helps them float, and stronger tissues with increase their strength. The hot gas, is probably hydrogen, easy to vomit up and spray out

 

[Redfrogcrab]

And I did give two plausible reasons. Dragon have hot gas which helps them float, and stronger tissues with increase their strength.

A. The hot gas theory is not plausible, maybe methane/hydrogen sacs, but still not that likely, gas sacks are too fragile for an areal predator (like a dragon), they are also too big, their's a reason why their's no balloon organism or organism with gas sacks for flight.
Birds do have hollow bones, not for mass reduction, but it's as close to gas sacks any flying vertebrate has
B. Yeah stronger tissue I can see that being a thing

 

[Redfrogcrab]

The hot gas, is probably hydrogen, easy to vomit up and spray out

If they actually breathed fire, I'd say it's either methane gas lit by a small eletrical arc (Maybe from some eletrical organ) or two highly reactive liquids (maybe some sodium compound and hydrogen peroxide) that auto-ignite when mixed

The acid theory came from the idea that stomach acid is really good at dissolving organic compounds and that mid-evil peasants mistook the acid for fire due, well, both burn skin, and it's way more likely for an organism to evolve controlled vomiting than actual fire breathing

 

[Ned Marcus]

Dragons operate outside the limitations of physics and biology. They're part of myth and fantasy, not science fiction. An SF writer friend once argued that dragons would be too big to fly at all. Perhaps he's right, but it's fun to make them fly. It's like the battle scenes in Star Wars. There's no sound in space, but it's more fun when they include the sound in the films.

 

[Redfrogcrab]

Dragons operate outside the limitations of physics and biology. They're part of myth and fantasy, not science fiction. An SF writer friend once argued that dragons would be too big to fly at all. Perhaps he's right, but it's fun to make them fly. It's like the battle scenes in Star Wars. There's no sound in space, but it's more fun when they include the sound in the films.

Oh just let us science nerds live in the fantasy that everything fits within science

 

[Redfrogcrab]

DRAGONS 2
WYVERNS
Wyvern I can genuinely see evolving from some kind of reptile (maybe some kind of archosaur or viranid lizard), Wyvern look like a pterosaur, with a pair of wings and a pair of limbs.

Same theory on the fire breathing and size limit to classic dragons, maybe slightly larger too

 

[Rexenm]

They are cold blooded birds. They fear noise, like a human fears pain. They also have brains in their tail. At least I have read of this. Or perhaps that was dinosaurs. But they eat gems, and use that to fuel their fires, and they can float, and rise up in the air. They are usually associated with shorter or thinner versions of humans. They protect maidens, dwell in towers of gold, and they see in the inverted spectrum. To how benevolent they are, I suppose you could call them evil, they get things like emotion upside down. They are fond of raw meat. They have no way of industry besides magic. They are known to be fiercely territorial, and loyal however. They are rarely seen fighting each other, because there is no point. They are much like spiritual renditions of elephants or cats, having some form of mystical bond to the plight of humanity, like they do. To their structure, it is very interesting and scientific to study, much like humanity, because they are obviously illustrations. They have modes and norms, much like humanity. However, like bears, they are vicious, in ways you cannot isolate. They enjoy stories and games.

 

[Insolent Lad]

In that my dragons are mammalian (related to the weasel tribe), I solved the fire breathing thing by having it come out the other end, a la skunks. And both my dragons and wyverns (which are flying reptiles) adhere to the sensible four limbs specification. However...in all the infinite worlds, in all their infinite variations, a six-limbed dragon could and would exist. One just hasn't found its way to 'my' world. And it might not be able to fly if it did, what with evolving under different basic physical laws. Assuming they evolved at all; some god or wizard somewhere might have created them.

 

[Redfrogcrab]

DRAGON BIOLOGY 3: I SOLVED THE FIREBREETHING PROBLEM
More accurately "fire spitting".
Anyways, all vertebrate animals make lots of flammable stuff, like methane, hydrogen sulfide, and (key to this speculation) fat

Historically, human for centuries have burned animal fat (specifically whale blubber) for light
So, what if dragons (at least fire-spiting ones) spit out and ignited liquid fat for fire

Why even breath fire?: for the same reason humans made fire, to "cook". Cooking food gets rid of fur, feathers, scales, parasites, and helps break down some food, allowing for easier digestion (its theorized that once homo erectus got cooking, the brains of humans got bigger with the added nutrition that comes with cooking)

Idea from draconology

 

[pmmg]

I dont want to be near Insolent Lads dragons....

Dragons seem to be widely regarded as being able to spew much more than fire with today's fantasy crowd. So...to cover all the breath weapons, you'll have some splaining to work on.

From what has been said already....

I think it likely dragons have different skeletal structure, such that the wings and forearms are both connect to the central bonal structures. If the dragons held on to gas, it would not need to the source of their flight, but something which made flight easier to obtain. It would not be fragile, as their scales are like armor and very hard to penetrate (if at all).

Dragons may gain their breath attacks from chemical reactions within their blood or stomach acids. Maybe their stomach acid is closer to kerosene, than acid.

But Dragon are creatures of myth and legend. They would seem on the scale of demons and angels....kind of ancient first kind of foes. I think by nature of being connected beyond the world of mortals, they can be afforded some explanations which science would have trouble accepting.

Ultimately, isn't the fact that their dont seem to be any actual dragons kind of evidence that science would not support them?

And also....

All those words, Wyrms, and wyverns and drakes and dragons... I am sure they all historically relate back to the same creature, but I kind of like that they have separation now.

 

[Redfrogcrab]

All those words, Wyrms, and wyverns and drakes and dragons... I am sure they all historically relate back to the same creature, but I kind of like that they have separation now.

Yeah, and for future reference:
Dragons: classic 4 legs-2 wings fire-breathing scaled creatures
Wyverns: 4 limbed reptile-like mythical animals, 2 wings, 2 legs
Wyrms: legless serpant-like animals with some dragon characteristics, also called Chinese dragons
Drakes: legless dragons

If the dragons held on to gas, it would not need to the source of their flight, but something which made flight easier to obtain. It would not be fragile, as their scales are like armor and very hard to penetrate (if at all).

Sure, but the gas sacks would have to be REALLY big, and would hinder maneuverability and arial speed. Assuming dragons are all mostly predatory animals, then gas sacs wouldn't be a advantageous trait for an areal predator to have

Ultimately, isn't the fact that their dont seem to be any actual dragons kind of evidence that science would not support them?

Just because it doesn't exsist NOW doesn't mean it CAN'T. If you stretch what a "Wyvern" is, then they already have existed as pterosaurs.

 

[pmmg]

Maybe dragon never come to believe they cant fly, and make the impossible happen.

 

[Redfrogcrab]

That's not how any of that works

 

[Redfrogcrab]

DRAGON BIOLOGY 4: DRAKES AND WYRMS

Drakes: easiest to explain, drakes are just wingless dragons, or just really big reptiles, a similar-looking creature did exist at some point, the giant extinct Monitor lizard Megalania which lived in Australia as recently as 50,000 years ago, and all the prehistoric archosaurs (reptiles including crocodiles and relatives, dinosaurs (and by extension, all birds), pterosaurs, and other extinct relatives). Drakes could be any old crocodylomorph or giant varanid lizard. Or they're some sort of proto-wyvern.

Wyrms: to my knowledge, Wyrms are flying serpent-like creatures, flying snakes are a thing IRL, they glide from tree to tree by flattening their body and pushing off trees, my guess is that Wyrms are just these snakes but on a much bigger scale.

 

[skip.knox]

It strikes me that if one takes Scientific Dragons to a forum of fantasy writers, one is going to get a lot of "well it's fantasy" replies.
If one takes Scientific Dragons to a forum of science fiction or even just science writers, one might get further along with the scientific logic.
And perhaps taking the topic to both might be most fruitful of all.