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Know Your History: Megatherium!

Before Clapp Laboratory, Williston Hall was the science building and possessed one of the most impressive collections of fossil casts, including the cast of the Megatherium americanum. The Megatherium was a species of prehistoric giant ground sloth indigenous to South America. The cast was bought from Henry A. Ward, who sold fossil and geographical casts. When the building burnt down in 1917, it was believed that the Megatherium burnt with it.

Nearly sixty years after the Williston fire, when exploring the newly renovated Safford Hall basement, Lorette Petersen ‘75 and Carmella Merlo ‘75 opened a closet to find the massive jaw of the Megatherium cast staring back. They alerted biology professor Curtis Smith, who organized the skeleton’s excavation from the closet. He led a class over the 1975 January term and with 25 students, cleaned and assembled the cast skeleton using the original armature, uncovered during the excavation, on the second floor of Clapp.

In 1987, the Megatherium was moved up to the fourth floor of Clapp, which was overseen by Professor Smith. Today, the Megatherium remains standing guard on the fourth floor, nearly 150 years since its purchase.
 Want to learn more about Clapp Laboratory? Be on the lookout this fall for a new exhibit in the Archives about the 100th anniversary of Clapp. 
Come visit the Archives from 1-4:30 pm Monday-Friday or contact us at for an appointment from 9:30-12 pm Monday-Friday,

Black and white photos along with blue blocks of text describe the discovery of a Megatherium skeleton cast.