The first known clutch of dinosaur eggs were found by American naturalist Roy Chapman Andrews (1884–1960) in 1922 in the Gobi Desert, south of the Altai Mountains. The eggs were found in one of the most prolific fossil beds in the area, a sedimentary layer known as the Nemget formation, which is also known for the more than 100 fossil skeletons of the small horned dinosaur Protoceratops.