First fossil record of the oribatid family Liacaridae (Acariformes: Gustavioidea) from the lower Albian amber-bearing site of Ariño (eastern Spain)

Abstract We describe the first beetle mite (Oribatida) found in the lower Albian (Lower Cretaceous) amber-bearing site of Arino, located in the Teruel Province (eastern Iberian Peninsula). It represents the first fossil record of the family Liacaridae (Acariformes: Oribatida: Gustavioidea). A new species, Liacarus (Procorynetes) shtanchaevae Arillo and Subias sp. nov., is described and compared with the living species of the subgenus Liacarus (Procorynetes). Notes on its biogeography and palaeobiology are provided. It corresponds to the first Cretaceous record of an extant oribatid subgenus and bears witness to the wide range of distribution that the ancient representatives of the subgenus may have had. Most of the oribatid species from Cretaceous ambers belong to living genera, which reflects the high degree of morphological stasis, or bradytely, over the evolutionary history of oribatid mites since the Early Cretaceous.