One of the new species is a type of ancient mammal called a shuotheriid, discovered in a Middle Jurassic fossil site in Mongolia, and has been named Feredocodon chowi. The other new species, Dianoconodon youngi, was found in the Early Jurassic Lufeng Biota in China and is more similar to a type of ancient mammal called morganucodon. Ecological reconstruction of Feredocodon chowi and Dianoconodon youngi reveals how mammals evolved our ears.
Both of these new species had special characteristics in their jaws and ears that indicate they were waypoints in the evolution of mammals from reptiles.