Overview

In this tutorial, we will cover the basics of quadruped anatomy! Understanding how the skeletal structure works for both humans and animals will help you visualize what you are drawing and make it more believable.

1. The Human Skeleton

First, let's breakdown the most important bones to know as an artist. These bones are the same in all animals, they are just different proportions from ours!

 

1. Skull

2. Spine

3. Ribs/Rib Cage

4. Scapula - the shoulder bone located behind the rib cage.

5. Humerus - the upper arm bone. Also known as the "funny bone"

6. Radius - the curved forearm bone.

7. Ulna - the straight forearm bone.

8. Pelvis

9. Femur - the large upper leg bone.

10. Patella (Knee Cap)

11. Tibia - the tibia is the large shin bone.

12: Fibula - the fibula is the small, lower leg bone.

2. The Three Main Body Parts

The three main body parts are in order from top to bottom: the Head, the Ribcage, and the Pelvis.

These are standard body parts for all animals with internal skeletons. Even whales! Knowing where these three body parts are in the animal is important because it helps you connect the rest of the body parts!

3. The Front Legs

The front legs of a quadruped (I will use a dog as an example) are the same as a human's! The main difference is the direction of the scapula. In the image below:

• Point "a" points to the scapula in the human example on the left and the dog example on the right. The scapula always connects to the humerus and forms the "shoulder".

• Point "b" is where the arm/front leg ends, forming the hand/paw. The hand/paw is connected to the forearm which contains both the radius and the ulna. Both humans and dogs have a radius and ulna.

• Lastly, Point "c" is the elbow. The elbow is the meeting point between the humerus and the forearm bones (the radius and ulna) in both humans and quadrupeds.

4. The Hind Legs

The hind legs of a dog are a bit different from the legs of a human, but the bones are the same! It all starts at the top with the pelvis. From the pelvis, the femur protrudes to begin the leg. After that, the knee, the shin (tibia and fibula), and then the heels and toes.

 

1. The heel in a human touches the ground, but a dog's does not. Although the heel is still considered a part of the foot. It is similar to a person walking on their tip toes instead of their entire foot.

2. The toes in a human are an extention of the foot, but the toes in a dog make up the entirety of the paw!

3. The knee is very similar in both humans and dogs. There is a femur above, a patella right at the knee, and the tibia and fibula are below.

4. The shape of a dog's legs can be tricky at first, but it is easier to draw when you imagine it like a lightning bolt!

Conclusion

I hope this brief introduction helps you get started drawing quadrupeds. Remember: the best way to get familiar with drawing animals is to draw them from real life and to study different animal anatomy. After all, both dogs and horses are quadrupeds but their skeletons are very different!