How to Draw - Comparative Anatomy

Comparative Anatomy

As you know, no two living things look exactly alike. It's important to understand your subject on a very deep level while you're planning your drawing. I'm not talking skin deep either, I'm talking about muscle structure and the skeleton.

When it comes to the way an animal is built, form follows function. In other words, if the skeleton looks a certain way, it's for a reason. There are few accessories in nature. So it's important to infer skeletal and muscular structure, even when you can only see the skin level of an animal.

For instance, we'll use the four different species of the Territory. Above is a quick study of a dragon's skull. On the left is the front view of the separated upper and lower jaw, without teeth. Notice how there are thick brows that protrude over the eyes? That creates a sort of shelf that functions like a shield, making the top of the skull flat. This also means a dragon can't see when it has its head bowed. The eyes of all four species in the Territory face forward, in what's called 'binocular vision'. Humans have binocular vision too, it's what gives us a stereoscopic, 3-D view of the world. Animals like cows and horses have their eyes on the sides of their faces, which gives them poor depth perception. To the right are a side view of the skull, with teeth, and finally a fleshed out skull.

Notice how large the nasal cavities are? Looking at areas of the skull like this can determine a lot of things about an animal's behavior. Big nasal cavities usually indicate a good sense of smell. By comparison, a dragon has only average eyesight and hearing. Compared to a lion or eagle's skull, which is more flat and short, these two species have excellent eyesight, and lions have big ear cavities for their large ears.

Such analysis can extend to the whole skeleton. For example, if you're drawing a lion, make sure that the fingers on the paws are rather thick. Why? Extra strong muscles are present at the end of each digit that help to push out a lion's retractable claws.

When it comes to wings, remember that a dragon's wing spokes are made out of stiff cartilage, not bone. The same goes for the spokes on the ears. This makes them slightly flexible, so they don't have to stick straight out at angles when you draw them. Eagles have a thumb and three finger feathers, which are slightly jointed just like a human finger.

Use comparative anatomy combined with the habits of your animal to help determine muscle structure. Lions are agile and thin, but are strong runners with powerful leg muscles. Dragons, by comparison, are stocky all over. Griffons and eagles both have thick necks, while a dragon's is more serpentine and flexible.

It's always useful to help solidify your drawings and make your characters more realistic by comparing them to other animals/people. Take the one thing that your character looks most like, and draw it. Then, draw your character in the same pose right next to it. You'll be able to pick out major similarities and differences in the anatomy, and this will help you memorize them. Keeping that in mind, your drawings from then on should be much more continuous from sketch to sketch, and all of them will look more realistic. Above are three such comparative drawings: two of a dragon and a horse, and one of a lion and a cheetah. Notice that although the animals are in the same poses, there are critical differences in the way their bodies are positioned, and this reflects differences in their anatomy. For example, both lions and dragons have thicker limbs than horses and cheetahs, so they cannot bunch their legs as close to their bodies during movement.

If you're drawing an animal, don't try to compare them to people! Animal bodies very rarely will match the pose of people. Our body structures and social behaviors are too different. Above is a quick sketch of a dragon and a human lying in the same position. Notice how their different body structures reflect in the way they are posed.

Lastly, a note about thumbs. All four species have opposable thumb claws on their forelimbs. Since these animals don't walk on the 'heel' of their hands or feet, the thumbs are held above ground, usually to the side of the foot. Eagles have a backward-facing fourth claw for grasping branches, like all modern perching birds, on their hind feet.

Don't forget our dear Ducks! Here's a quick comparison of a standard duck, and Disney's anthropomorphized version.