American Mastodon

Indiana designated the American mastodon as its official state fossil in 2022, making it one of the most recently adopted state fossils in the country. Mammut americanum was a large elephant relative that lived across North America and disappeared about 10,000 years ago at the close of the last Ice Age.

Indiana's glacial landscape made it ideal mastodon habitat. Shallow lakes, spruce forests, and shrubby wetlands provided the food and water mastodons needed. The same glacial sediments preserved mastodon bones across the state for more than a century of discovery.

The American mastodon was a stocky, heavily built animal that stood about 8 to 10 feet tall at the shoulder and weighed 6 to 8 tons, roughly the size of a modern African elephant. It had long, slightly curved tusks that could reach 8 feet in length, and a thick coat of dark brown hair.

Mastodons are often confused with woolly mammoths, but they were distinct animals. Mammoths had ridged molars for grazing grass; mastodons had low, cusped molars built for crushing leaves, twigs, bark, and woody shrubs.

Mammut americanum went extinct roughly 10,000 to 11,000 years ago, at the same time as dozens of other large Ice Age mammals. Climate change and human hunting are both considered contributing factors, and the debate about which mattered more is still active in paleontology.

Indiana had no state fossil until students at Randolph Southern Elementary School in Winchester began studying state symbols and realized the gap. The students chose the American mastodon, wrote letters to state legislators, and testified before the Indiana General Assembly in support of the designation.

The campaign succeeded in 2022, when the Indiana General Assembly passed the designation and Governor Eric Holcomb signed it into law. The mastodon was a natural fit. Indiana has produced hundreds of mastodon finds, and specimens are on display at museums across the state.

The most significant Indiana mastodon find is the Megenity Mastodon, a nearly complete skeleton discovered in Harrison County in southern Indiana in 1960. It was recovered from a sinkhole on the Megenity farm and is now on display at the Indiana State Museum in Indianapolis. Its completeness made it one of the most studied mastodon specimens in the Midwest.

Northern Indiana, particularly the counties of Lagrange, Whitley, Marshall, and Kosciusko, has produced a large share of Indiana's mastodon finds. The region's glacial lake beds and ancient bog deposits preserved bone exceptionally well, and many specimens came to light during 19th- and 20th-century farm drainage projects.

Mastodon bones have turned up in at least 90 of Indiana's 92 counties, from highway construction, well-drilling, and riverbank erosion. Indiana's high find count reflects both the density of mastodon populations during the Pleistocene and the state's extensive agricultural and development activity.