Mastodon Mastodon Mastodons (Greek: μαστός "breast" and ὀδούς, "tooth") are any species of extinct proboscideans in the genus Mammut (family Mammutidae), distantly related to elephants, that inhabited North and Central America during the late Miocene or late Pliocene up to their extinction at the end of the Pleistocene 10,000 to 11,000 years ago. Mastodons lived in herds and were predominantly forest dwelling animals that fed on a mixed diet obtained by browsing and grazing with a seasonal preference for browsing, similar to living elephants. "M. americanum", the American mastodon, is the youngest and best-known species of the genus. They disappeared from
Mastodon (steam locomotive) Mastodon (steam locomotive) Mastodon was the unofficial name of the Central Pacific Railroad's number 229, the world's first successful 4-8-0 steam locomotive. The engine was designed and built by the road's master mechanic, Andrew Jackson "A.J" Stevens at Sacramento Locomotive Works in 1882. The locomotive had two highly unusual features: the firebox shape and the steam distribution. The only other locomotives to use such a valve gear were the 20 copies of "Mastodon" (see below) and CPR #237 "El Gobernador." All other steam locomotives with slide valves had just a single valve in the center. After being readied for its