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61

The creatures eat rocks. The excreta from this is fertile loam that is ideally suited to farming. They can be trained to eat from rock formations in such a way as to create walls and fortification. If they eat a metal ore, the metal part is not digested and can easily be separated from the loam to produce pure gold/silver/iron etc. A problem is of course ...


53

Actual brazillian here. The reason why you won't find any mountable animals in the amazon rain forest is because it's kinda like a more green, lush version of Australia, in the aspect that half of the biomass is out to kill you in horrible ways. It is a [redacted] to go through the jungle, on foot or otherwise. And the river waters can be classified in ...


46

We have a historical precedent for a world with monsters the size of houses. The difference was arguably higher carbon dioxide, and tropical temperatures, leading to richer and more vibrant plant life. I'm not sure how much it contributed, but the age of the dinosaurs was also largely before plants were mostly composed of cellulose, which is extremely hard ...


38

Usually such creatures are at least partly based in magic and therefore don't need the usual degree of physical sustenance that would be expected. If you want to ignore this and go for purely biological solutions I suggest referencing Australia's saltwater crocodile which can and will lay up for months hibernating between meals; your dragons don't need to ...


35

No, but plenty of their relatives can A moose or elk would die in the high heat and with limited resistance to insects and such. They simply aren't designed for the rainforest. However, there are plenty of animals large enough to mount that are native to a rainforest, and a rainforest alone. Bongo Lowland Anoa Okapi These animals are not domesticated, so ...


24

In my story, there is a civilization living in the Amazon rainforest. They need some time of mount that is adapted to the forest. There are Buffalos in the Amazon (in the Brazilian state of Pará) and they can be used to mount: They live primarily near farmlands (in the Amazon region), but they have been adapted to live in the same climate as the forest. ...


17

Like whales, your dragons feed on krill-like insects After all, whales are also "castle-sized", and they manage to find enough food in a sustainable way. So, your world contains legions of very small flying insects, swarming quite passively. Your dragons have found a way to harvest a lot of them efficiently (a blue whale can eat 4 tons daily). This may add ...


14

So there's only a few ways this could happen 'realistically'. 1) Water comes from underground. This would require a lot of really unlikely scenarios though and probably wouldn't be stable for long. Imagine a tube running from under the oceans all the way to the middle of the mountain ranges. Then having the temperature and pressure force the water to the ...


13

When you keep the environment temperature constant, you can make your beasts ectotherms. That would reduce their need for food, since their metabolism would not need to maintain a constant body temperature. They could much more easily survive longer periods of time without food. If you add a rich vegetation that is capable of maintaining large herbivores (...


13

Let's do some basic math; Australia is approximately 4000km wide, and a good figure for an average walking speed is 5km/h, meaning that in total it would take around 800 hrs to walk from one side of a continent like Australia to the other. BUT: It's never as simple as that. For a start, it's not a perfect plain, food and water is not going to be ...


11

Maybe they eat uranium/thorium, have stomachs that enrich the fissile elements and extract energy from nuclear fission. Or they have a breeder reactor on their guts. You will need magic to save their cells from the hot neutrons and gammarays.


11

Dragons eat outside the terrestrial biosphere House sized dragons don't need to eat on the surface of the Earth. Perhaps they just like to rest here. Take the idea that they eat plankton to the next level: they eat something that exists outside of the food chain interactions of the planet's surface. The most obvious answer is the ocean. Lets say your ...


11

Putting climate and disease environment aside, because kingledion covered them, there is the issue of antlers and rainforest growth. Rainforests don't have an open understory the way mature conifer or oak woodlands do, as such anything that grows a large rack of antlers is seriously maladapted to moving around and feeding in the environment. There is ...


9

Would vulcanism work for you? Vulcanic eruptions can create flowes without rain. The obvious candidate would be Magma flows. This is the moon Io, magmaflows of basalt lava crawl over the surface for hundreds of kilometers [6]. If you want liquids other than molten rock, check out cryo-vulcanism [1]. Water, ammonia, methane or some mixed slurries don't ...


7

Yes and no. you can make it work by having a hard ground: Mercury is heavy. 13 times denser than water, so I would put it into a not too deep, flat lake with some kind of solid rock bottom. More importantly: Mercury is very much not reactive, and it does not corrode. So have no worries about it corroding away. Another problem is that it will evaporate. Very ...


6

Okay, first of all, we'll need to figure out how much food it really needs. Let's say your dragon is the size of an Amphicoelias fragillimus, a real castle-sized land animal, which is estimated to have weighed 120,000 kilograms. Assuming a reptilian physiology, the dragon would need to consume 1.2 million kilocalories a day. Damn. That's what the formula ...


5

Can't happen with an Earth-like planet How do you move millions of tons of water from lower elevation to higher elevation? On Earth, the only mechanism to do so is evaporation of water into the atmosphere. If you want no rain or snow, then that is ruled out. What other mechanisms could possibly move such a large mass of water without evaporating it? There ...


5

Dragons are beach scavengers in the model of Tyrannosaurus - or the condor. Here is my answer to this question. Mythical dragon diet http://www.montereycountyweekly.com/news/local_news/condors-make-a-meal-of-a-beached-gray-whale/article_aabcf553-a462-502d-8809-93225ba069f1.html The California condor is (!yay) the largest North American bird. After the ...


5

Underground Water Credit to Liam Morris If there is no surface water on your world, perhaps there are underground rivers and lakes. Plants could evolve to grow their roots into these waters and their leaves would grow on the surface. Imagine caves like these where roots hang from the ceiling as though they were stalactites all around the world. Animals ...


5

Can a plant survive a 3 month period of no luminosity (or at least in amount that does not provide enough light to sustain any photosynthesis)? Yes, it's called WINTER, in case of polar night the tolerated period without light can be even longer. Being bioluminesent would be quite expensive from evolutionary perspective. There would be an evolutionary ...


4

My piece of advice is one related to preventing them from being murdered by our good friend the square-cube law. You will want to probably give them a really low metabolism (which also happens to reduce food requirements), and make them ectothermic. That way they won't absolutely burn up. Or you could make them endothermic but really resistant to heat and ...


4

Tides (lots of handwavium here) Imagine that your planet is really very flat, but it has some very wide craters, whose rim is high just a dozen meters above sea level. It also has a massive moon on a very elliptical orbit. Every N months (Earth months, for that planet it is once a month), when the moon is at the nearest, the tide makes the sea flood into ...


4

For comparison, Roman soldiers were expected to march 30 km (20 Roman miles) a day with 20 kg equipment. The march itself was expected to take 5 hours, for a mean speed while marching of 6 km/h (a fast walking speed). The rest of the time was spent foraging and setting up camp, camping, and striking camp. 20 kg is a lot of baggage to carry around. According ...


4

10 thousands year is an awful lot of time for a river. Just look at how the Netherlands changed in the last 600 years: Or look at how the Po river delta changed over the past 300 years: The Adriatic sea is called like this because of Adria, a city which was once a big port and now is several kilometers inland. And the examples above only deal with the ...


3

The first thing which comes to my mind is having a water cycle similar to the one we have on earth, except that instead of raining the water condenses only once near the top of the mountains, and drips directly back to the rivers/glaciers. It's not very different from what we have, and probably happens sometimes on earth, when correct temperature/pressure ...


3

Our oceans come from volcanic activity lifting gases out out of the world's core. A world like you describe naturally forming to be volcanic enough to support chemotrophs without oceans is not very likely. The closest you could come is a runaway greenhouse world like Venus with VERY tall mountains. At 55km, Venus's atmosphere is Earth like except for ...


3

The easy answer is "yup! mountains!" the truth is more complex Sometimes we get caught up too much in "reality." In "reality," this planet cannot exist as you've described. But what's the fun in that? Therefore, I'm going to utterly ignore all aspects of physics that would either (a) tear this planet apart or (b) force it to eventually become spherical. ...


3

Yes, just like plants on Earth create stores of energy in their roots to survive winter, your plants could develop a similar strategy of survival. It is also very likely that the leaves of said plants will fall off during this darkness period as leaves take energy to maintain and would not be returning energy without light. As for human survival, the plants ...


3

In the 1830s-1860s, caravans of Conestoga wagons and livestock and children traveled the 2000 miles from Eastern Nebraska to Western Oregon in about 7 months. Includes traversing multiple mountain ranges. That's roughly 15 miles a day across easy terrain, 5 miles a day across difficult terrain, with daily time for foraging, cooking, laundry, making and ...


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