San Diego Zoo Global
San Diego Zoo: Warthog
This resource provides detailed information about the warthog, as well as several pictures.
University of California
Ucmp: Introduction to Artiodactyla
This site explores the artiodactyla, and includes a focus on fossil records, life history and ecology, systematics, and morphology.
PBS
Nh Pbs: Nature Works: Bighorn Sheep
Learn more about the bighorn sheep through this informative resource. Students will gain a deeper understanding of the bighorn sheep's habitat, reproduction, behavior and more.
Wikimedia
Wikipedia: Bovid
Some factual information on bovids can be found in this Wikipedia encyclopedia article. There is also a table that provides scientific classification information on bovids as well.
Other
The Ultimate Ungulate Page: Order Artiodactyla
An excellent site that provides a good description of Artiodactyla and then provides full descriptions of many of the different animals.