The Hall of Mammalian Evolution
Mastodon Skull
The Otisville Mastodon (skull) Mammut americanus YPM catalog no. 12600

Renovation Closure Announcement

The Great Hall and the Hall of Mammalian Evolution will be closed starting January 1, 2020, for the duration of the upcoming Peabody Museum renovation.


The fossils in this hall, from the Yale Peabody Museum’s collections in the Division of Vertebrate Paleontology, belong to the main groups of mammals that evolved during the Cenozoic Era (65 million years ago to the present), after the extinction of the dinosaurs. During this time mammals diversified into a wide variety of carnivorous, herbivorous and omnivorous forms. Overlooking the hall is the 60-foot mural The Age of Mammals, painted by Rudolph F. Zallinger in 1964, which dramatically illustrates the evolution of North American mammals during the Cenozoic Era.

Some of the largest fossils on display in Hall of Mammalian Evolution include the Otisville Mastodon (Mammut americanus) and the huge Brontotherium, both acquired in the 19th century by Yale’s O.C. Marsh.