Dragon

This article is about dragons.

Dragons (singular: dragon) are the reptilian or serpentine vertebrates that comprise the family Draconem. Species therein include the amber dragons, ruby dragons, pearl dragons, and obsidian dragons, among others. According to lore, they can be broken into two groups: Celestial and Terrestrial, though only the latter is known to truly exist.

Terminology
While there is not official terminalogy to differentiate between male and female dragons, terms such as "drake" and "bull" have been used for males, "queen" and "cow" for females. For those that are born in eggs, "hatchlings" is used for young dragons, while "dragon young" is used for those that are live-born. A group of dragons is usually referred to as a "flight" or "clan."

Habitat
Dragons are widely distributed, with indigenous representatives in all regions of the world. They live in a variety of biomes, though with more emphasis on warmer environments than not. All currently known species of dragon can be found in the continent of Vallhyn.

Biology
Dragon weights generally average to around 7,000 kg (15,432.4 lb), with the lightest species, the jade dragons (Vollosus sinensis), averages 1,050 kg (2,314 lb) and the largest, the ruby dragons, averages closer to 14,700 kg (32,408 lb). Gender-wise, females were generally larger and heavier than their male counterparts.

From tip to tail, the average adult dragon can reach past 40 feet long, again with variations. In this case, however, it is the male dragon that is longer than the female. This is believed to be due to mating and activity practices, as male dragons are generally more prone to fly, and the lessened weight and longer body allows from higher maneuverability.

In general, dragon scales are made of lightweight keratin, like the hair and nails on a human. While hatchlings' scales have a more round appearance, as the dragon grows, the number of scales increases and gives them a V-shaped appearance. This reduces drag, allowing the dragon more speed while in the air.

Brain to body mass is around 1:.002, giving them the largest brain size of any known living creature, with a brain weighing up to 14 kg. Encephalization quotient measurements vary from 4.5 to 7.6, depending on the species.

It is understood that dragons are warm-blooded creatures, assumed due to their high-energy lifestyles that can only be supported by warm-blooded metabolism and evidence of endothermic metabolism found during autopsies. This also allows some species to live in cold environments without ill-effects on health.

In terms of lifespan, dragons are biologically immortal, much like lobsters. This is theorized to be due to constant cell replenishment from transdifferentiation. To date, there are no known records of a dragon dying of a natural death, and as such it is difficult to gauge normal lifespans. Most deaths are due to inter-dragon violence and fighting. Similar to lobsters, dragons actually do not stop growing. As such, the size averages listed per any given dragon species is based on known measurements and records. It has been noted, however,  growth rate slows with age and differs according to species.

Health concerns for dragons include obesity, arthritis, low fertility, gout, and aggression between dragons. Stereotypic swaying has also been observed in captive dragons, particularly the ruby dragons

Eating Habits
Their digestive system is significantly shorter, in order to allow for more room for muscle mass. Due to their shorter digestive track (shorter in order to allow for more torso muscle to better enable flying), dragons tend to eat many small meals over time (as opposed to a single large meal). Metabolism is also fairly high for those dragons that fly often, but have been found to be quite low when dragons are in a hibernation-like state or when ground-bound. This shorter digestive track is conducive to flatulence, from which the air sacs of the dragon gain the methane gas.

On average, adult dragons require about 40,000 calories per day (though dragons that constantly fly have far higher requirements). This is equivalent to about 1 human every two days.

Those of the genus Rostralis are omnivores, and are characterized by rough skin and beaked mouths. These dragons tend to prefer open environments such as deserts or grassland. In contrast, the Hypsilophus tends toward carnivorous behavior, having a predilection towards more enclosed areas, such as forests. The genus Alca is also carnivorous, while the genus Vollosus is comprised of herbivores. Both these genera are often found in high-altitude areas in cooler climates.

Flight
While young, dragons (excluding genus Vollosus and some of genus Hypsilophus) are incapable of flight, largely due to underdeveloped wings. It has been observed that many of these young will flap their wings absently throughout daytime activities, building up the needed muscle.

Once fully grown, dragon wings are actually fairly short and broad compared to it's body size, allowing for high maneuverability. As the dragon relies far more on lifting power than gliding, it uses its long tail as compensation. Because of this, cutting of the dragon's tail often prevents the beast from ever flying again.

As for how dragons are capable of flight itself, this is largely due to two factors: hollowed bones and air sacs along the dragon's flanks. The former helps alleviate weight from the beast, making it easier to fly, while the air sacs inflate with a methane gas (routed from the digestive track), giving the dragon a psuedo-balloon style of flying.

The torso muscles are also heavily developed, filling in much of the cavity. This constant motion means that active dragons have a rather low body fat ratio. This means that as a dragon gets older (and therefore less active), its body fat ratio increases, slowly rendering it ground-bound. That said, dragons do not generally fly constantly. Instead, their time is more generally found on the ground, though there is great variability between species.

Reproduction
Mating seems to be largely based on by the male's aerial agility and the size of his hoard. It is not uncommon to see two or more male dragons attempting to woo a single female dragon. In live-birthing dragon species, one to two young are born and up to six or eight can be born to egg-laying species. Young mortality is generally fairly high for most species.

Scientific Classification

 * Kingdom: Animalia
 * Phylum: Chordata
 * Class: Anthracosauria
 * Order: Rhynchocephalia
 * Family: Draconem

Taxonomy
The family is broken into several genera:


 * Rostralis ('with a beak'), named for the beaky mouths
 * Rostralis arvensis (amber dragon)
 * Rostralis echinatus (ruby dragon)
 * Hypsilophus ('high crest'), named for the relatively high foreheads
 * Hypsilophus caecus (pearl dragon)
 * Hypsilophus repens (obsidian dragon)
 * Vollosus ('hairy'), named for the hair-like manes
 * Vollosus sinensis (jade dragon)
 * Alca

In Culture
All species of dragons feature prominently in Vallhyn lore and myth. It is said that dragons were actually the first race crafted by the gods, something they attempt to perpetuate.