See text Meridiolestida is an extinct clade of mammals known from the Cretaceous and Cenozoic of South America and possibly Antarctica.

[1] Meridiolestidans were morphologically diverse, containing both small insectivores such as the "sabretooth-squirrel" Cronopio,[2] as well as the clade Mesungulatoidea/Mesungulatomorpha, which ranged in size from the shrew-sized Reigitherium to the dog-sized Peligrotherium.

[3] Meridiolestidans are generally classified within Cladotheria, more closely related to living marsupials and placental mammals (Theria) than to monotremes, barring one study recovering them as the sister taxa to spalacotheriid "symmetrodonts".

Lakotalestes from the Early Cretaceous of North America, originally identified as a dryolestid, was noted in one paper to have a tooth morphology closer to that of meridiolestidans.

[8] A possible meridiolestidan is known from a tooth fragment, now lost, found in the La Meseta Formation from the Eocene of the Antarctic Peninsula.