Today, we know that the bones from William Clark's expedition represent several extinct mammal species: woolly mammoth, American mastodon
muskox, ancient horse, ancient bison, and stag moose.
In 1989 the skeleton of an American mastodon
, Mammut americanum, was unearthed in Newark, Ohio.
The ancestors of the American mastodon reached North America from Eurasia via the Bering land bridge during Miocene time, approximately 18 million years ago.
These were the American mastodon (Mammut americanum) and the Jefferson mammoth (Mammuthus jeffersoni).
Paleontologists found the tusk of an Ice Age elephant, possibly a Columbian mammoth, bones and teeth of a towering American mastodon
, wood and pollen from incense cedar and Mormon tea plants and fossils of birds, shrews, cottontails, gophers and mice.
Skeels (1962) summarized all known records of both the American mastodon and Jefferson mammoth in Michigan; at that time 32 localities were recorded, only 16 of them represented by museum specimens.
These dates indicate that the Jefferson mammoth and American mastodon were contemporaries in Michigan during the Wisconsin lateglacial and possibly early postglacial times.
The first report of the American mastodon
(Mammut americanum) in Michigan was during the nineteenth century (Lanman 1839).
Osteology for the Archaeologist: The American Mastodon
and the Woolly Mammoth.
Mammut americanum, Utah's first record of the American mastodon
BIOGEOGRAPHY AND STABLE ISOTOPE ECOLOGY OF AMERICAN MASTODONS (MAMMUT AMERICANUM) FROM THE ATLANTIC COASTAL PLAIN: EVIDENCE FROM A NEW MASTODON FROM NORTH CHARLESTON, SOUTH CAROLINA **, C.
Some argue that it was a humanborne microbe that did in the North American mastodons
, camels, and giant sloths at this time.
And, this region is important because it included the "heartland" of so many important and interesting large mammals, such as mammoths, American mastodons
, giant beavers, and Scott's moose.