An opilioacarid mite in Cretaceous Burmese amber.

Abstract

A fossil opilioacarid mite (Parasitiformes: Opilioacarida) in Burmese amber is described as ?Opilioacarus groehni sp. nov. This ca. 99 Ma record (Upper Cretaceous: Cenomanian) represents only the third fossil example of this putatively basal mite lineage, the others originating from Eocene Baltic amber (ca. 44-49 Ma). Our new record is not only the oldest record of Opilioacarida, but it is also one of the oldest examples of the entire Parasitiformes clade. The presence of Opilioacarida-potentially Opiloacarus-in the Cretaceous of SE Asia suggests that some modern genus groups were formerly more widely distributed across the northern hemisphere, raising questions about previously suggested Gondwanan origins for these mites.