Incredible Living Fossils: Horseshoe Crabs
Also known as the King Crab, the Horseshoe Crab is not actually a crab at all, as it’s much more closely related to spiders and mites. Horseshoe Crab-type creatures started showing up around 400 million years ago and around 170 million years later, the species evolved to what we still see today.
34 million years ago the Chevrotain’s home was fairly widespread, but now it’s found only in Southeast Asia and Central-West Africa. Although it looks like a tiny deer (the Asian variety is known informally as the Mouse Deer), its ancestry is not so clear cut.
It does share the usual deer trait of having a many-chambered gut to digest vegetation, but differs in that its third stomach is much less developed. It also has four toes like a pig and elongated canine tusks.