Let's imagine there actually were dragons (dinosaurs) that spit fire.

How could that be actually proven if you've lived in a day and age like today, where these kinds of creatures are actually extinct and all you have left are fossils.

I guess residual analysis would be helpful. But then again these flammables produced by "dragons" should quickly evaporate as compared to oil, I could imagine it more like gas and that might be difficult to prove.

  • 1
    $\begingroup$ We have "relicts"? What, some species of such dragons survived? Or do you mean fossils? Scientists can deduce quite a lot about the ancient creatures from their fossils. As for the specific topic, you may want to find and watch Justin Hardy's The Last Dragon (also known as Dragons: A Fantasy Made Real); it's a well-made directly relevant pseudo-documentary. $\endgroup$
    – AlexP
    Feb 8, 2020 at 22:13
  • $\begingroup$ Oh yes, you're right. Forgive me, I meant fossils. Thanks! $\endgroup$
    – at_
    Feb 8, 2020 at 22:19
  • 1
    $\begingroup$ Do watch the British pseudo-documentary... Click on the link to YouTube. $\endgroup$
    – AlexP
    Feb 8, 2020 at 22:27
  • 1
    $\begingroup$ Discovery Channel did a documentary on exactly what you’ve just asked. The whole thing is centred around an autopsy of a ‘found’ Dragon and among many characteristics covered you’ll find your fire breathing. Can anyone remember the documentary’s name? $\endgroup$ Feb 8, 2020 at 22:27

1 Answer 1


The biggest thing would be signs of burn marks on fossil bones and the inner side of dragon teeth

The only parts that reliably preserve in fossils are hard tissues. Bones, teeth, etc. In rare cases you get mummified skin or soft tissues preserved, but this is rare. As a result, anything that isn't preserved in bones is very difficult to figure out.

This goes for most of the squishy stuff that people have recovered from fossils. Muscle size and usage in feeding and locomotion comes from attachment scars on bones. Evidence for diet and migrational patterns comes from differences in chemical isotopes in bones. Behavioral inferences like herding or parental care come from unusual associations of bones. Dietary habits come from comparative anatomy or bones/shells within a rib cage. And so on.

The idea that dragons breathed fire would best be inferred based on something left on bones. Burning leaves marks on bones that are inferrable even after fossilization. In paleoanthropology, such evidence is used to infer human usage of fire. Evidence of burning in weird environments might imply fire-breath, though that requires accurate inference of paleoenvironments where forest fires are rare (e.g., a rainforest or a desert). Even then, researchers might interpret dragon burns as evidence of infrequent forest fires. A skeleton where only part of the body was burned as if hit by a flamethrower rather than all over as if exposed to a forest fire would be hard to explain. Additionally, these burn marks would only be on prey or other animals, you would rarely find burned wood or charcoal like you would expect if the burns were from forest fires.

The biggest sign that dragons breathed fire would be their teeth. Because dragons breathe fire from their mouth, the inner face of the teeth would likely be singed because that's where the fire is coming from. I believe Dragons: A Fantasy Made Real and Dragons and Unicorns: A Natural History pointed this out. As reptiles, dragons would likely replace their teeth regularly (especially if they were regularly being exposed to flame), and would be pretty common in the fossil record. These shed teeth would show signs of being heated on one side, signs of charring or being stained by smoke, or unusual heat-resistant enamel.

This would be true even if dragons aren't really breathing fire and are really breathing some bombadier beetle-like chemical or vomiting stomach acid. The teeth of humans with bulimia or who frequently engage in vomiting show signs of acid wear on the inside face of their teeth due to exposing them to fairly acidic vomit. Dragon teeth would look the same.

Eventually, the combination of signs of fire being used in a manner more similar to flamethrowers than forest fires in paleoenvironments that really have no business having forest fires and burn marks on the inside of dragon mouths would suggest to researchers that dragons are the cause, and that somehow the fire is getting inside the dragon's mouth. Causation or correlation wouldn't be clear at first. Some kind of fire-breathing mechanism would be considered more likely than dragons being so stupid they tried to eat fire.

Isotopes might also help if dragons have some kind of weird metabolism in order to breathe fire, and store unusual carbon/oxygen/nitrogen isotopes or elements in their bones. However, isotopic studies have really only come into vogue in the last 15 years in paleontology, so depending on the techbase of your setting it might not be reasonable.

  • $\begingroup$ This was an amazing reply. Thank you so much! That is, what I was looking for! Thank you! $\endgroup$
    – at_
    Feb 9, 2020 at 12:50
  • $\begingroup$ Not as conclusive as you think, I dug a dinosaur with burn marks, the deposit it was found it was determined to be a forest fire induced land slide, based on the land slide deposit combined with a lot of charcoal in the deposit. The animals was already dead when the fire happened (the bones showed signs of rot) Also fire really doesn't do much to teeth. $\endgroup$
    – John
    Apr 29, 2021 at 20:24
  • $\begingroup$ @John Right but the thing is you'd keep finding burned dinosaurs. Way more often than one would expect if they died in forest fires if dragon's fire breath is used for hunting or defense. On top of that it would be possible to tell from the taphonomy that the bones were burned perimortem. The sheer number of burned bodies that kept turning up would suggest something unusual was going on and a new explanation was needed. $\endgroup$ Apr 30, 2021 at 0:46
  • $\begingroup$ Absolutely a large sample size would help, but we don't know if they would have that, A lot of dinosaurs are only known from one or two specimens. Also consider how many will actually have burn marks, very few bodies will ever be burned, and teeth don't show much fire damage especially non-mammalian teeth that are shed periodically. humans show acid marks because of continuous exposure over many years, if a dragon is like a dino it will not have any teeth more than two or three years old. $\endgroup$
    – John
    Apr 30, 2021 at 1:19
  • $\begingroup$ @John But that's the exact point. Under normal circumstances very few bodies are ever burned. But OP is talking about animals that regularly use fire to hunt or as a defense mechanism. If there is a huge spike in fire-damaged skeletons in the fossil record that suggests something is different in the environment compared to the the present day. $\endgroup$ Apr 30, 2021 at 4:16

This site is temporarily in read-only mode and not accepting new answers.

Not the answer you're looking for? Browse other questions tagged .