 A recent study (2011) places Leptanillinae as a sister group to all other ants, with Martialinae, the poneroids and formicoids forming a clade.Ants first arose during the mid-Cretaceous, more than 100 million years ago, associated with the rise of flowering plants and an increase in forest ground litter.The earliest known ants evolved from a lineage within the aculeate wasps, and a recent study suggests that they are a sister group of Apoidea.