I enjoy my BIO classes, they allow me to go all out, and give me an excuse to study animals I'm rusty with. I never drew dogs or wolves much, so these were good practice.
It was difficult to find an anatomical drawing of a wolf skeleton and its musculature online or in books. There are lots of diagrams for those of its domestic descendants, but not so much for the original animal. I drew the skeleton below from museum photos. I don't know if you can tell, but I'm impatient with vertebrae when it comes to studies.
The wolf has a very particular face, the angles have to be just so, or else the animal will come out looking like a dog, or coyote. These are simple proportion and facial studies from photos, done in preparation for the perspective drawing up top. I had a page of wolves drawn from the zoo, but the enclosure was so difficult to see into, and the animals so distant, that not many of the sketches were good for cleanup. Though some may have snuck into the page below.
Related article: A tattoo designed for a client based on the red riding hood fable. Lots of unfriendly canines in trees~