Originally, I was going to save this until I had finally illustrated all of the dragons and proto-dragons that I had dreamt up and put them all into a nice cladogram. However, given the strangely high popularity of Part 1, I decided that it best not to leave my readers hanging. Perhaps, some time in the near future, I shall finally get round to finishing my illustrations and be able to share my first complete cladogram for the phylogeny of my fictional world.
I have previously shared these on Hive, and will include additions as I make them, even if it’s just a single illustration. You can see the fragments that contributed to this post here, here, and here.
The crown, or origin, of all Varanganskan dragons is a six-legged arboreal dinosaur called Epihexapodosaurus, a name which means “more than [just] a six-legged lizard.” Environmental changes, specifically widespread flooding in prehistoric jungles, drove many animals up into the trees. Dinosaurs, which are defined primarily by their hips, were adapted to high-speed bipedal running on the ground, but “reverted,” for lack of a better word, to a shape that superficially resembles a six-legged lizard (actually, aside from snakes, all Varanganskan lizards alive at the time of The Nine Empires have six legs).
Epihexapodosaurus spread far and wide, and while some of the areas it moved to remained the same, some dried out, and the animals adapted to a more terrestrial lifestyle, as their ancient ancestors had. Their legs thus became more adapted to running, but the changes that had built up resulted in a different body shape from earlier dinosaurs. So began the lineage of “dog-lizards,” owing to their body plan and lifestyle reminiscent of canids.
Each of the dots, or nodes, on this cladogram is arranged in the order it appeared chronologically. Furthermore, nodes are arranged with basal forms placed lower than more derived specimens. Therefore, the dog-lizards, being the most basal descendants of Epihexapodosaurus, are the bottom branch. You may notice that some of these are brown and furry – this is because these dog-lizards lived in colder climates, and thus their fibrous proto-feathers grew into thick coats. One of these dog-lizards is so stocky for the purpose of preserving body heat that it resembled a bear, but made from a dinosaur. This one is called Arctosaurus, which literally means “bear-lizard.” At the same time in much warmer climates lived a dog-lizard with a long, slender body, and with rows of spines instead of fluff. Its head crest also reminded me of Spyro the dragon when I finished it, so I called this one Spyrocyonosaurus, literally “Spyro the dog-lizard.” Descended from it are the earliest and most primitive of viviparous dinosaurs, and thus the first true dragons, the great serpents.
Megaserpentes (a name I’m sure I don’t need to translate) was the first true dragon, and its descendants did one of two things: either they kept the same body shape and went back up into the trees, or they traded in their legs for flippers and adapted to an aquatic lifestyle. The aquatic (later marine) lineage is the only one to survive to the modern day, as I mentioned before, and while the extant specimens don’t have limbs at all, they all started out like this:
Going off on a brief tangent, the more derived lineage of dog-lizards specialised their front pair of limbs into brachiodonts, which are structures that I mentioned before in my post about dire toads (Batrachosuchus), and then again when I described the quasi-mammal Plesiotherium, also called a burrowing walrus. I did this mainly for fun, and also because I wanted an excuse to make something that looked like a tyranid:
Dog-lizards had just barely begun to differentiate themselves between the lineage that would become dragons and the lineage that developed brachiodonts before, back in the jungles where Epihexapodosaurus had first emerged, some interesting things were going on with actual lizards as well. One lineage, for no discernable reason, shortened its body and lost a pair of legs before adopting an arboreal lifestyle, and sometime thereafter, adapted the forward of its two pairs of remaining legs into wings. Other lizards had evolved the means to glide before (in the real world as well as in my fictional one, there’s even one such lizard alive today), but none had ever done so in a manner that could lead to powered flight. Thus began the lineage of wyverns, which drove competition with arboreal dinosaurs, which copied them and improved upon the design.
Dinosaurs were endothermic (warm-blooded), and their higher metabolism than ectothermic (cold-blooded) animals, such as lizards, made them much more suited to powered flight. Initially, these flying dinosaurs were not that impressive, and started out gliding, just as lizards did before them. The differences between the wing structures is more easily seen below in a close-up of the sequence.
As they became more specialised for powered flight, the row of dorsal spines separated into two patches: one on the head, which eventually became a head crest, and one on the tail, which eventually became a tail fin. Both of these acted as rudders on the more specialised descendants, including the first true flying dragon.
These two different lineages evolved differently based on their flying style. Though these two illustrations are fairly similar, you can already see noticeable differences between Tetradactylopteryx on the left and Pseudodactylopteryx on the right. The names, incidentally, refer to a four-fingered wing and a “false-fingered wing,” respectively, as the dragon wing is supported by a spine protruding from the elbow as well as all four fingers. The wings themselves are also shaped differently, as longer, thinner wings are more suited to gliding than to flapping. Tetradactylopteryx, as you may have noticed on the cladogram, isn’t a true dragon, and doesn’t have all of the necessary adaptations for powered flight that true flying dragons do. However, these flying dinosaurs grew to be far larger than any actual dragon, and the discovery of a partial skeleton of a descendant, Gigantopteryx, a somewhat pterosaur-like flying dinosaur the size of a Lancaster bomber, led to the myth of the cloud-jumper, a giant dragon that the sky gods rode. However, while the mythical cloud-jumper may be depicted in artwork as simply an exceptionally large dragon, and it may have have feathered wings, the Gigantoperyx specimen that inspired the story had a toothless beak – something that no true dragon has. To be fair, however, the myth originated long before anyone found a specimen with an intact head.
Meanwhile, true flying dragons didn’t get particularly big, and their wings ended up being distinctly different for two reasons. First, larger species of flying dinosaurs retained a functioning thumb claw, which they used as an anchor. Smaller animals didn’t need to do this, and in dragons, the first step was to lengthen the thumb and connect it to the first finger with a membrane, thus creating a leading-edge flap. This ultimately led to the thumb becoming the same length as the other fingers, creating a five-fingered wing additionally supported by the elbow spine. The crown of this lineage is Acanthopteryx, or “spiny wing.”
The wings became shorter and wider over time, as one would expect for fliers that relied more on flapping than on gliding. Furthermore, true dragons and large flying dinosaurs occupied different environments and fulfilled different roles, with dragons typically remaining in forested areas and hunting in the trees (which is how they wiped out the wyverns). Gigantopteryx and others like it, meanwhile, hunted in open areas, including the open ocean, keeping their nests in cliffs (for reasons that ought to be obvious).
The next part of this series will discuss the third and final branch of the dragon cladogram, which leads to both feathered dragons and birds. Think of it this way: if birds are dinosaurs, doesn’t it make more sense that the dragons we typically see in fiction would also be dinosaurs, rather than lizards?