Linked from
The 28 pages that link to Evolution of mammals, each with the reason it gives.
MonotremeNarrower topic: Monotreme origins belong to the early diversification of mammals.
MammalogyNarrower topic: It connects living species and fossils into a shared history.
PalaeotheriidaeNarrower topic: Palaeotheriids belong to the Paleogene radiation of hoofed mammals.
SolenodonNarrower topic: Solenodons preserve an ancient branch of Caribbean mammal evolution.