Skeletal and Muscular Structure

A dragon’s head is perhaps the most well-armored part of its body. All dragons have some sort of “crown”, or an arrangement of crests and horns, on the tops of their skulls. The shape, size, and nature of this crown varies depending on species; most Lesser Wyverns have a smooth plate of bone with two horns branching from the back of it; many Saurians have sharper, spiked crests with two to six horns and spikes on the ridges above their eyes. The purpose of these crowns is primarily for defense-- an enemy dragon cannot bite the skull of its opponent without risking breaking a tooth or, in the cases of dragons like Firedrakes, injuring itself on a spike. Dragons with spiked crowns tend to have spiked jawlines as well to protect their throat. The horns themselves are made from bone, but have an enamel coating similar to teeth. Horns are typically long, smooth, and straight, but some species have shorter and thicker horns, while Greater Wyverns grow theirs in curled segments. Like the crest, a dragon’s horns are typically for defense, though may have secondary effects-- locking horns with an enemy dragon to gain leverage, creating a larger profile for intimidation, and even cutting air resistance in flight. Very old dragons may develop extra branches on their horns, or barbs near the tips; the purpose of these is unknown, and seem only to be decorative.

A dragon’s skull varies by species. However, since all dragons are carnivorous, all species have similar dental patterns. In each quadrant of the jaw (both upper and lower), most dragons have two fangs, the front of which is longer and thicker than the one behind it; some species only have one fang here. This is accompanied by two or three incisors at the front of the jaw, two or three more canines behind the fangs, two carnassials, and three to five molars. There may be more molars on the bottom jaw. The exact counts of these vary wildly by genus and species, but are fairly consistent otherwise. All of a dragon’s teeth are serrated except for the molars, which are used to crush bone and rock; moreso the latter, in search of metal (see Dietary Needs). In more aggressively predatory species, like Saurians and Wyverns, the front of the snout may be hooked slightly downward, almost like a beak; this is to allow the dragon a better grip on its prey, which may otherwise struggle and break free, ripping out the dragon’s teeth. Dragon teeth regrow quickly and seemingly without limit; old dragons often appear snaggletoothed after centuries of hunting and fighting. A dragon's bite strength generally varies from 1000 psi in Lesser Wyverns (enough to very easily snap bone) to nearly 4000 psi in Greater Wyverns and Heavy Saurians (enough to bite through and gnaw solid steel). The only exception to this is the Voidwalker, with a bite strength of merely 350 psi- still several times stronger than that of a human.

Dragon eye sockets are narrow and angular, which when combined with the crown, makes the skull have a lean and sharp profile. All dragons have forward-facing eyes to grant them the binocular vision typical of a predator; even species which seem to have their eyes side-facing orient towards the front. The pupils are narrow but round in most species, but some dragons do have slitted pupils. More detail can be found under Bodily Systems and Body Language; however, a dragon’s eyes are protected by the ridge of bone above them, which in some species can also give the appearance of a permanent scowl.

The bones of a dragon are strong, dense, and sturdy, but surprisingly lightweight. In fact, with the exception of flightless dragons, the bones are hollow. Internally, the bones have a spongy lattice similar to that seen in birds, but are overall thicker, making them more difficult to break. The thickest bones are the skull, vertebrae, and limbs; the thinnest are the wing fingers, which are the most liable to break from injury due to their long, thin shapes. Dragons that can fly do so through completely physical means, utilizing aerodynamics to balance their weight and streamlined shapes. Similarly to birds, their wings move in a way that moves air underneath them, thereby creating lift and forward thrust. If a dragon must remain in a hover for an extended period of time, they do so by entering a mostly vertical position, only partially downstroking their wings, and moving their tails in a manner counter to their wingbeats in order to maintain their rough positions. A dragon cannot hover forever, but they are one of the few creatures that can do it at all.

Dragons have four to six limbs, and even then there are outliers, such as one Genus with eight. All limbs are tetradactylous, and all hind legs are digitigrade. All dragons with four non-wing limbs are quadrupedal. Dragons with non-wing forelimbs have opposable thumbs and are able to use them as hands, though no quadrupedal dragon can truly walk on its hind legs (although most can briefly rise up on them). The fourth, innermost toe on the hind legs acts as a dewclaw, helping the dragon keep its footing on uneven terrain and helping to keep a struggling prey animal pinned. In most species with wings, there are three fingers connected by membrane and a fourth “thumb”; however, in Greater Wyverns, there is one long wing finger holding the membrane and a three-digit claw the dragon uses to walk on.

Dragons are coated in hard, smooth scales made from keratin, Mythril, and trace amounts of other metals. These scales are largest near the dorsal line and smallest on the face and digits. Large species may develop thicker, almost plate-like scales on the spine, which are not truly plates but rather deposits of excess metal acting as armor. The development of these scales can cause irritation similar to teething, but ultimately they are beneficial by acting as extra armor. Contrary to popular belief, most dragons do not lack scales on their ventral sides, they are simply much smaller; those that do lack scales, however, replace them with leathery plates or “scutes” which can deflect human weapons or glancing blows from another dragon and protect the throat, neck, and abdomen. More details on dragonscale can be found under Scale Structure.

Dragons have powerful muscles attached to their limbs, which accounts for much of their bulk. The most powerful muscles are found in their shoulders and haunches, the former to support the work the wings must put in to take flight and the latter to support some of a dragon’s less-used fighting tactics: jumping, rearing, and using the hind legs to pin and gut an enemy. The muscles in the jaw are also well-developed, leading to the sheer bite strength larger species display. Surprisingly enough, the neck and tail are also heavily muscled; I personally assume this is to help protect the neck from being forced into dangerous positions by an opponent and to help the tail maintain position during flight.

A dragon’s scales cover thick, tough, leathery hide. Known as “dragonhide”, or “dragon leather” when used by humans, this hide is supple and flexible despite its thickness and generally a duller shade of its scale color due to runoff of the pigment; see Scale Structure. Despite its overall toughness, dragonhide scars fairly easily if not protected by the scales but is not easily torn or pierced. Thinner scales cover the dorsal sides of the wing membrane, but the membrane itself is not made of quite the same material as the hide. Wing membrane can still be damaged and ripped from the edges or the ventral side, and while torn membrane eventually does regrow, it can take anywhere from days to months depending on the extent of the injury. Dragon wing membranes are elastic, able to stretch out to great volumes when the wing is fully extended but partially contracting in on itself when folded; this allows the wing to effectively catch air even when folding partially to steer a turn or dive.

Lastly, dragons are frequently covered in some sort of decoration. Most dragons have small spikes on their joints, most commonly the back of the forelimb elbow and hind limb ankle. Spikes and plates along the dorsal line are extremely common, although these also serve a functional purpose. The crown can often be mostly decoration, and the tip of the tail frequently carries some sort of barb, blade, or “tailspade”, the general term for a tailtip decoration with no function. Many dragons have sails of some sort; others have manes of fur, which often end in a tuft on the end of the tail. The fur in particular has no particular purpose and seems mostly to be for attracting mates.

Bodily Systems

Dragons, particularly the larger species, have robust internal organs and bodily systems. In order to support their size and weight when hunting, flying, and fighting, the respiratory and circulatory systems are particularly advanced and efficient; a dragon’s heart is very large relative to the rest of its organs, and while heart rate isn’t particularly fast, the blood naturally carries a much higher concentration of oxygen than ours does. The efficient flow of blood allows them to carry out strenuous activity much longer than most creatures-- namely long-distance or high-altitude flying, but also the aerial acrobatics many species display for the fun of it. A particularly agile dragon may fly in loops and sharp swoops, but feel no ill effect from blood rushing to or away from the brain.

Dragons are homeothermic, which in layman’s terms means their blood is warm and regulates their body temperature from within; they do not have to sunbathe like reptiles do. This allows some species to live in harsh tundra climates or on mountain peaks, as well as granting a defense from strong, cold winds at high altitudes. Despite their ability to regulate their own body temperature, certain species still have a very low tolerance for cold and prefer warmer conditions, or will even weaken and die in cold climates. A dragon’s natural blood temperature is, however, much higher than that of most mammals and birds, and is what we would consider hot to the touch.

Aside from the heart, the lungs are the most specially-evolved organs in a dragon’s body. Long and powerful, a dragon’s lungs are valved off of the windpipe to prevent a blowback of fire, venom, and smoke. The valve is only closed in circumstances that warrant it; largely, this only includes combat involving fire or venom and hunting underwater. The valve remains open all other times, including during flight; the act of flapping forces air into the dragon’s lungs and makes it impossible for them to roar, speak, or breathe fire until they stop flapping and settle into a glide. While this seems a strange evolutionary trait, I believe it to be so that a dragon does not accidentally fly or dive into its own flame.

The brain and nervous system of a typical dragon is complex, and doesn’t have as many neat parallels with our own as one may hope in my line of work. Though the brain still seems to be lobed, like ours, and is superficially similar structure to a mammal’s, the organ is longer and narrower-- more like a reptile’s-- and usually situated directly underneath the crown of the skull where it is most protected. What equates to the frontal lobe in our brains-- the area which controls reasoning, critical thinking, and memory-- is one of the largest and most developed areas of a dragon’s brain, followed closely by what I think controls the senses… which is where parallels with our brains begin to fall apart. A dragon’s vision, hearing, and to an extent its sense of smell are all controlled by very close areas of its brain, so much so that they may simply be different regions of the same lobe. The spinal cord connects directly to what seems to control motor functions and sense of balance, possibly aiding in flight, hunting, and fighting. This is most blatantly seen in the Voidwalker, which must maintain its balance not only in water but what is effectively a vacuum, and which is notoriously hard to knock off of its feet.

There are several other areas of the brain, with fairly reasonable functions… for the most part. There’s a level of something arbitrary to how even our brains are laid out, and we understand the brain of a dragon even more poorly. There’s a section that seems to handle prey responses, but it’s completely separate from hunting and combat instincts; in fact, it seems to share a lobe with the dragon’s sense of time. The optic nerves do not lead into the area which controls vision, but rather that which handles involuntary action such as heartbeat. A small section near the brain stem seems to do absolutely nothing… and yet “goes dark” when the dragon is under the effects of Dracoimpery. The oddities and intricacies of the brain of a dragon are better explained by a true scholar. I’m just writing a book.

Straying away from the biological puzzle cube that is the brain, the nervous system proper is downright simple, though also poorly understood. The nerves are densely bundled, allowing the dragon much more accurately sensitive tactile senses. The denser concentration of nerves allows dragons reflexes which rival- and were likely inherited from- Shapeshifters. Though they lack the “sixth sense” that allows Shapeshifters to evade danger before they know it’s there, a dragon is quick to respond to any sort of stimulus. At rest, a dragon can go from dozing to awake, alert, and focused on whatever caught its attention in an instant. Even dragons cannot explain how they sense something’s presence nearby; often they claim they simply “feel it in the air”.

A dragon’s eyes are highly adapted to almost any typical circumstance. They have very dense retinae, granting excellent distance vision exceeding even that of eagles, and are able to pick out small details on the ground from miles in the sky. All dragons-- though particularly those that are nocturnal-- have adapted a layer of tissue in their eyes seen also in cats-- the tapetum lucidum, a reflective layer just behind the retinae, which increases their sensitivity to light. Additionally, while most dragons do not usually dive into water, most develop a protective film over the eyes in response to moisture. This membrane rapidly dries when no longer needed, and allows the dragon to see clearly when submerged or flying in heavy rain. The eyes of a dragon naturally seem luminescent, though this is, in most cases, a trick of their reflectiveness. More detail can be found under Body Language.

Even the digestive system is finely attuned to the stranger nuances of how dragons behave. Because dragons eat metal, and do not always have access to human-forged coin and jewelry, many wild specimens will directly eat ore out of a vein (see my notes on how their dental arrangement helps with this, above in Skeletal and Muscular Structure). In doing this, much of what the dragon eats will be junk ore and rock, with the metal sparsely distributed across it. To bypass this, a dragon’s stomach acids and bile are both highly acidic, dissolving the undesired materials while leaving the metal. The rock is passed quickly through the rest of the digestive system and is generally expelled within an hour. The metal itself is dissolved and processed more slowly, by enzymes rather than acids. While the liver and related organs produce and store bile that eases the breaking down of fat, the fact that it deals so handily with rock is a prime example of nature multi-tasking. A dragon's kidneys are also specialized in a way that allows the processing, filtering, and expulsion of minerals and metals which would be harmful to their biology-- particularly lead and quicksilver, which must be transmuted or expelled.

Scale Structure

Dragonscale is one of Euthora’s strongest-- and strangest-- materials. Like most scaled reptiles, the scales of dragons are made from a hard keratin base, similar to their claws-- however, in dragons, the scales are not part of the skin as they are in reptiles. In fact, the development of dragonscale is far more similar to that of a bird’s feathers. The keratin is produced from a follicle-like cavity which holds the scale root, the nerves attached to it, and an oil-secreting gland. Through some strange combination of genetics, the structure of the cavity, and gradual wear from nearby scales, the developing scale ends up a long, narrow shape with a distinct point. Though the specifics of the shape vary by species-- Voidwalkers have rounder, blunter scales while Firedrakes are very well known for scales so sharp and serrated that the legs of any rider would be shredded-- all species share the general narrow, keeled structure. The keel runs almost the entire length of the scale and is merged with the root, which is generally three-pointed. This root structure makes the scales strongly attached to the dragon’s skin, like the root of a tooth, and overall reinforces the strength of the scale itself.

The most curious thing about the structure of the scale lies in the follicle. In addition to the nerve endings and muscles required to allow the dragon to move its scales, the root also attaches to the creature’s Mana Circuits. For those not inclined towards magic, Mana Circuits are the “structures” in our bodies that allow us to use Mana; in effect, to allow us to use magic. What this means for the dragon is that the Mana Circuit feeds directly into the scale, which stores it seemingly indefinitely, allowing the dragon a much larger source of Mana than its body should be able to store at one time. Dragons are not inherently inclined to be mages (barring the Voidwalker), but they use Mana for a number of things; see Fire Breath under Notable Abilities for the primary example.

All of this is possible due to the most important material in dragonscale: Mythril. Though most commonly found in veins underground, the metal Mythril is naturally synthesized in the scales of all dragons; it alone is why dragonscale is so valuable to human society. Mythril has the property of absorbing and retaining Mana, most useful in enchanting jewelry and weapons, or allowing a mage a small emergency Mana reserve; in dragons, it is mostly an advantage of a strong, lightweight material for use as armor. Mythril is naturally a bright, shiny silver with a subtle blue sheen, however the glands found in the follicles of the scale secrete an oil-based pigment which both dyes the metal and slightly dulls its luster. This oil, most commonly called Dragonscale Oil or Dragon Oil, has a strong and pungent odor many describe as similar to badly charred fish; this is a large part of why most dragons smell like woodsmoke. Despite the oil secretions, scales are naturally hard, dry, and smooth without leaving any sort of residue like hair and fur does.

Alongside the oil, the glands below dragon scales produce a sort of “metal sweat”; the metals dragons crave and ingest are dissolved within some organ all dragons have, and this dissolution in turn is excreted with the pigments, eventually hardening into a plating that protects the scale. Research has shown me that this is a sort of “internal alchemy” the bodily systems of all dragons undergo-- ingesting metal, breaking it down, internally transmuting it into higher metals, with Mythril being the goal. This is why dragons prefer precious metals-- such as gold and silver-- despite the high weight and low hardness, over stronger but cheaper metals such as iron and copper. Dragons can subsist on these lower-tier metals, but need much more of it, or they will develop a metal deficiency. Metalloids can occasionally be used as a substitution to mixed effect, but metals alloyed with nonmetals-- like iron and carbon combining to make steel-- cause a somewhat interesting effect. The dragon’s body will go out of its way to separate the iron from the carbon, in this example, and only process the metal-- the nonmetal, carbon, is rejected as bodily waste (this is a specialized example of a dragon’s digestive acids separating metal from rock; see notes in Bodily Systems). However, because of the alchemical process, dragonscale is not pure Mythril-- it contains trace amounts of all the other types of metal the dragon has eaten.

A metal-deficient dragon contends with many afflictions, the most prominent of which is scale corrosion. In a corroded scale, the follicle isn’t secreting the metal dissolution, and thus as the scale grows and is worn down the metal plating is scratched off, exposing the keratin beneath. While this causes the dragon no direct harm, it lowers the effectiveness of scales as armor and causes a very visible effect: the scales becoming white-edged. Corroded scales are very brittle and will not defend against the attacks of another dragon. Sometimes, however, a dragon’s scales will be the victim of more incidental conditions; some dragons simply do not produce Dragon Oil. This leaves their scales as Mythril’s natural color and sheen and is a form of albinism; even species which are naturally silver produce the oil to dull the luster. Outside of those species, predominantly silver dragons are very rare-- the reflective brightness of Mythril catches light too easily and often scares away the dragon’s prey, leading it to either scavenge or starve. A side effect of the oil, as well, is that it protects the Mythril from tarnishing; tarnished Mythril leaks its stored Mana, so a dragon that does not produce Dragon Oil will eventually have a permanently lessened stock of Mana to draw from.

Dragons are also subject to parasites which nestle under the scales. Mites are common to all scaled or feathered animals, dragons included; those living in wooded terrain may gather ticks. Only the smallest parasites will successfully latch onto a dragon, due to the family’s thick hide; most pests are unable to pierce the skin, but the smallest may be able to squeeze into the follicle of the scale and bypass the skin altogether. Chief among these is a creature that exclusively parasitizes dragons, the scale mimic. Scale mimics burrow under a scale, loosening it until it eventually falls out, and then settles into the hole the scale left. From here, it feeds on the oil and metal and chews away at the keratin of the new scale, preventing it from growing back in. Because of its diet, it grows a shell of chitin and metal that looks almost indistinguishable from the dragon’s real scales; only close inspection will reveal its different texture and hardness. Most dragons have one or two scale mimics; they do not cause irritation in small numbers and do not carry any diseases dragons can incubate. The danger comes in that scale mimics are not useful as armor, and a dragon with too many will be more vulnerable to attack. Scale mimics rarely breed on a dragon's body, and are more prone to reproducing within the dragon's lair, using shed scales and terrain to hide from their host. They may become a nuisance if a nest is present.

Of course, dragons are not the only creatures which derive use from their scales. We humans will use it as currency which goes for a high rate; Mythril coins are not common in most of the world and in some areas, particularly Seotara and Durasken, dragonscale is much easier to come by. Aside from currency, we use either the whole scale or the metal from it for decoration, jewelry, armor, weapons-- in fact, many smiths take advantage of the fact that the Mythril is naturally alloyed with such metals as iron and copper. They take this natural alloy and combine it with larger amounts of iron and carbon to create a hard, strong, light alloy called Dragonsteel.

Sometimes, Dragonsteel armor and weapons are combined with one or two colors of Dragon Oil. Most commonly, only one color is used, to simply dye the metal-- however, when two or more are used, the smiths can create intricate patterns in vibrant colors that will never wear out. These pieces are regarded as mastercrafts and sold at a premium. Dragon scales, metal and keratin both, can be superheated and ground to create a high-quality resin called Fyreglaze. This resin, made from ground dragonscale, comes in multiple quality grades (water-based being the cheapest, followed by blood- or oil-based) and is used to coat a weapon (usually a blade) and protect it from general wear. Dragon Oil can be used as an expensive oil base for the resin, resulting in a distinct sheen on the treated weapon.

Reproduction and Maturation

This section strictly focuses on the physiological aspects of reproduction, nesting, and maturation. For the social aspects of this topic, see: Courtship and Nesting under Wild Instincts.

Dragons are oviparous, and depending on species will lay a varying number of eggs, known as a clutch. When nesting and rearing young, the male is known as the sire, and the female is known as the dame. A newborn is known as a hatchling. A clutch can be anywhere from one to six eggs, not all of which will survive long enough to hatch. Dragon eggs have a hard, dense shell primarily made of calcium carbonate, with a high metal content consisting mostly of Mythril. When the dragon hatches, its instinct is to eat its own eggshell; this gives the hatchling’s scales a headstart in developing in a healthy manner.

Dragon embryos develop rapidly within the egg, even before leaving the mother. A freshly-laid dragon egg is typically ready to hatch within days, but may spend months or even years developing further, both physically and mentally, before the confines of its egg begin to make it claustrophobic and hatch. More information can be found under Ancestral Memory in Wild Instincts, but in short, the infant dragon’s mind is most likely sorting through all of the information available to it from its ancestors, and is assigning different pieces to instinct, inherent knowledge, and latent memory. Most hatchlings will be able to break free of their egg without help, but occasionally the shell may be thick enough that it requires a helpful bite from a parent to give the initial crack.

The species of a hatchling can be either of the parent species, or a hybrid of the two, with about an even chance of either result; however, eggs in the same clutch trend towards the same result. Because of this, it is possible for a dragon to produce more of its species even if it seems to be the last of its kind; this is thought to be a holdover from latent Shapeshifter genetics, which favor repopulation of a dying or even extinct species where applicable. Hybrids can, in turn, produce more of their particular kind of hybrid, or further hybridize with the mate's species. This tends to lead to rapid speciation of a crossbreed within a few generations of the first hybrid.

A clutch will lean primarily towards males in a rough 2:1 ratio, which is both an evolutionary counter to the higher likelihood of a male dying in combat, and incidental to the Ancestral power source, detailed in its own section later in this book. Hatchlings mature quickly, growing exponentially in size for their first few years of life and slowing in growth as they reach adolescence. A hatchling becomes an adolescent when it learns how to fly (an age which varies wildly for each species, but is generally between 5 and 10 years), at which point it becomes known as a fledgeling. Fledgelings leave the nest soon after mastering flight. In species that are flightless, adolescents are known as drakes (not to be confused with the Order Microdrakontes, in the next chapter) and the threshold of maturity varies depending on species. Most species then reach adulthood somewhere between 30 and 40 years of age, aside from the Shadow Drake, which reaches adulthood closer to 20.

Morphological Classifications: Introduction