What is "dryolestida"

Dryolestida is an extinct order of mammals; most of the members are mostly known from the Jurassic to Paleogene, with one member, Necrolestes, surviving as late as the early Miocene. It has been suggested that these mammals are either the possible ancestors of therian mammals or an offshoot from the same evolutionary line. It is also believed that they developed a fully mammalian jaw and also had the three middle ear bones. Other than that, not much is known about them, this is because their fossils are made up mostly of jaw and tooth remains.

Dryolestids were formerly considered part of Pantotheria and/or Eupantotheria. The clade Quirogatheria, erected by José Bonaparte in 1992, is often used as a synonym for Dryolestida. Originally, Quirogatheria was meant to include Brandoniidae, but this family is now included with the dryolestids.

It has been suggested on the basis of morphological evidence that they may still be extant in the form of marsupial moles. However, a molecular study places marsupial moles within Euaustralidelphia, though several problems with this assessment have been addressed.