Who are the ancestors of mice? - briefly
The immediate ancestors of modern house mice are extinct early muroid genera such as †Paleomys and †Prolagus, which appeared in the Oligocene after the Glires clade split from lagomorphs about 70 million years ago. These early murids form the basal branch of the family that later produced the genus Mus in the Miocene.
Who are the ancestors of mice? - in detail
Mice belong to the order Rodentia, a lineage that diverged from other mammals during the early Cenozoic era. The earliest known rodent fossils date to the Paleocene, about 66–56 million years ago, and exhibit primitive dental patterns that foreshadow later murine characteristics.
Key stages in murine ancestry include:
- Paleocene‑Eocene basal rodents such as Alagomys and Paramys; these taxa possessed incisor enlargement and gnawing adaptations that set the foundation for later forms.
- Miocene Apodemus‑like genera; these ancestors displayed the characteristic three‑molars and a robust skull, bridging the gap between early rodents and modern murids.
- Late Miocene to Pliocene murids including species of Mus and Rattus precursors; dental morphology became increasingly specialized for omnivorous diets, and body size stabilized around that of present‑day mice.
Genetic studies corroborate the fossil record, indicating that the subfamily Murinae split from other murids roughly 12 million years ago. Molecular clock analyses suggest that the genus Mus originated in South‑East Asia before dispersing into Europe, Africa, and the Americas through successive land bridges and human‑mediated transport.
Overall, the ancestry of mice traces a continuous progression from primitive Paleocene rodents to the diversified murine clade of the modern era, marked by incremental dental specialization, skull remodeling, and geographic expansion.