University of California
Ucmp: What Is a Sabertooth?
A good review of the natural history of the extinct species, the Sabertooth. Includes pictures of bones of this animal.
Smithsonian Institution
National Museum of Natural History: American Mammals: North Pacific Right Whale
The right whales have been driven nearly to extinction as the species preferred by commercial whalers and have been hunted in spite of international bans. There are perhaps several hundred in the western Pacific, and perhaps only a...