Introduction to the Proboscidea
Elephants, Mammoths, Mastodons
There are only two species of Proboscidea alive today: the Indian elephant (Elephas maximus) and the African elephant (Loxodonta africana). In the past, however, a diversity of unusual elephant relatives traversed areas around the world. The most famous of these extinct relatives are the mammoth and mastodon, but there were also shovel-jawed gomphotheres and other, less familiar groups such as the deinotherians. The precise relationships between the various groups of proboscideans are not well-understood (Kalb and Froelich 1994).
Proboscideans, like hyraxes and embrithopods, evolved and diversified in Africa during the Paleogene. The oldest proboscidean is a meter-high unnamed animal from the Lower Eocene of Algeria (Mahboubi et al. 1984). Throughout the Upper Eocene and the Oligocene, extensive fossils of large proboscideans are known. During the Miocene, proboscidean groups emigrated to most other continents, becoming a widespread and important group until the extinction of most species in the Pleistocene.
Elephants are sometimes called pachyderms, a term that also applies to rhinos and hippos, and refers to their thick skin. These other pachyderms are not closely related to the elephants, however. Rhinos are perissodactyls, related to horses, and hippos are artiodactyls, related to pigs and camels.
In addition to their unique morphology, modern elephants are unusual among mammals in two key respects of their social structure. Firstly, they have a matriarchal social structure, in which herds consist of related females led by the oldest among them. Males tend to be solitary, but may come together in small herds. Secondly, baby elephants are given care and guidance for several years longer than most other mammals. During this time members of the herd may care for the babies, regardless of which is the mother.
Follow UCMP's summer 2005 excavation, in text and photos, of a partial mammoth skeleton discovered in San Jose.
The Elephant Information Repository has lots of elephant pictures and links to all kinds of elephant information.
You can learn more about extinct Proboscidea from the Pleistocene of the Midwestern US exhibit at the Illinois State Museum, including a QuickTime VR image of a mastodon tooth.
The Nova Scotia Museum of Natural History has an article about a 1991 mastodon discovery.