The artwork that matches the described characteristics is the San Rock paintings at Shelter Cave, Southern Africa. These paintings were made in caves, used natural pigments derived from minerals or clay, depict animals (often related to hunting), and do not employ shading to create a sense of roundness.
The other options mentioned, such as the Aboriginal cave paintings or the Chinese horse cave painting (which may refer to the Lascaux cave paintings), either do not fit all the specific criteria or are not accurately represented by the descriptions provided.