Russian scientists have described a new genus and species of early placental mammals. They were able to make this discovery based on a jaw fragment from the Early Cretaceous site of Khobuur in the Gobi Desert, Mongolia. Prozalambdalestes cratodus is the oldest representative of the Zalambdalestidae family and sheds light on the early stages of this family’s evolution. Regarding the descendants of Prozalambdalestes, scientists have not yet reached a definitive conclusion. One hypothesis suggests that its descendants are modern rodents and lagomorphs. Prozalambdalestes cratodus is the largest placental mammal in the Khobuur mammal complex. Its name is related to the close genus Zalambdalestes from the Late Cretaceous of Mongolia and reflects the presence of strong molars. The new form also differs from other Zalambdalestidae by the position of the mental foramina, the slanted premolars, and the wide rear lobes of the lower molars. The Khobuur site is known for its numerous finds of diverse mammals, including multituberculates, eutriconodonts, symmetrodonts, archaic therians, and early placentals.