AMNH 9951, skeleton of mastodon (Mammut americanum), Newburgh, NY
Museum preparators working on the brontothere collection, early 20th Cent.
Expedition to the Fayum Basin, Egypt, 1902
Museum president Henry Fairfield Osborn (center) with paleontologists Walter Granger (right) and Albert Thomson (left), 1930
Specimen preparation, 1956

While they may not attract the public attention of the Museum’s dinosaur collections, fossil mammals have always been a key component of vertebrate paleontology at AMNH. Henry Fairfield Osborn, who arrived in 1891, was himself a mammal paleontologist and was responsible for hiring several outstanding vertebrate paleontologists with interests in fossil mammals: these included William Diller Matthew, William K. Gregory, Walter Granger, and Jacob Wortman. In 1895, the Museum purchased E. D. Cope's collection of c. 10,000 North American fossil mammals; the Cope collections became the kernel of the paleontological collection, containing many important type specimens.

The fossil mammal collection grew under the guardianship of Osborn, who became Museum President in 1908. Important expeditions were made to the Fayum Basin, Egypt (1901); the Bridger Basin of Wyoming (1903, 1904), the White River Badlands of South Dakota (1906), and the Miocene Agate Springs site of western Nebraska (1919). The Central Asiatic Expeditions of the 1920s, under the direction of Roy Chapman Andrews, although best known for their dinosaur discoveries, made extensive collections of Cenozoic mammals.

In 1916, the Department of Paleontology began a long association with Childs Frick, the son of steel magnate Henry Clay Frick and a longtime American Museum trustee. Using his personal fortune to employ a small army of collectors, Frick accumulated a collection of over 200,000 fossil mammals, which formed the basis of a series of monographic studies on mammal evolution. The collection was donated to the Museum after Frick’s death in 1965.

After Osborn's death, in 1933, the fossil mammal collection continued to grow through the activities of a succession of outstanding curators, including George Gaylord Simpson (South America), Malcolm McKenna (Mongolia; Wyoming), and Richard Tedford (Australia; New Mexico). The financial assets of the Childs Frick Corporation, which were donated to the Museum along with Frick’s fossil collections in 1968, assisted in the construction of a new, 10-story collection and office building, which opened in 1975.

In recent years AMNH Provost and Senior Vice President Michael Novacek has reestablished the long standing ties between the Museum and Central Asia, making a remarkable series of discoveries in Mongolia which are providing new insights into the evolution of mammals. Similar close field research and training collaborations in paleomammalogy are underway in China (Meng Jin) and South America (John Flynn).