Two new species of the bristle millipede genus Pauropsxenus (Diplopoda, Polyxenidae) in mid-Cretaceous Burmese amber

Two new species of the bristle millipede family Polyxenidae, Pauropsxenus ordinatus sp. nov. and Pauropsxenus extraneus sp. nov., are described from the mid-Cretaceous Burmese amber. They can be confidently placed in the extant genus Pauropsxenus (Polyxenidae) based on a set of critical characters. In additions, the morphological similarity of hooked caudal trichomes shared by the new species and extant counterparts may suggest a similar defensive function. Our discovery indicates that a prey-predator relationship between polyxenids and other soil animals has already been established in the Cretaceous period.