Micromomyidae (Micromomids) is a family of extinct plesiadapiform mammals that include some of the earliest known primates.[3][4] The family includes five genera[5] that lived from the Paleocene epoch into the early Eocene epoch.[4]
Micromomyids first appeared in the fossil record between 61.7 and 56.8 million years ago with the Micromomys genus. All but one specimen has been discovered in modern-day inland North America, more specifically in Wyoming, Alberta, and Saskatchewan,[5][6] with one unlabeled Eocene species found in Shandong, China.[6]
Like other known Plesiadapiformes, it appears that the micromomyids were small, tree-dwelling insectivores.[4][5][7] They are thought to be some of the smallest of their order, with estimates for some species around 10-40g,[4][7] or one-third to one and a half ounces, in weight.