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

Antonio Arillo,Luis S Subías,Sergio Álvarez-Parra

doi:10.1016/j.cretres.2021.105087

Antonio Arillo, Luis S Subías + Show 1 more

Open Access

https://doi.org/10.1016/j.cretres.2021.105087

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Abstract

We describe the first beetle mite (Oribatida) found in the lower Albian (Lower Cretaceous) amber-bearing site of Ariño, 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 Subías 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.

Highlights

Beetle mites (Oribatida) are common in almost all terrestrial ecosystems, and comprise more than 10,000 described species (Subías, 2004, updated online version 2019)
We describe a new oribatid species from the lower Albian (Lower Cretaceous) amber-bearing site of Arin~o, which belongs to a living genus and subgenus of the family Liacaridae and represents the first fossil record of the family worldwide
The new species clearly belongs to the subgenus Liacarus (Procorynetes), in view of the short tail and the clubbed head, slightly truncated, on its apex

Summary

Introduction

Beetle mites (Oribatida) are common in almost all terrestrial ecosystems, and comprise more than 10,000 described species (Subías, 2004, updated online version 2019). Some estimations have placed the number of oribatid species in the world fauna as high as 50,000e100,000 (Schatz and Behan-Pelletier, 2008). Because of their minute size, they are rarely found in the fossil record, especially in pre-Cenozoic strata, and are mostly associated with amber deposits from the Cretaceous onwards. The oldest oribatid mites date from the Middle Devonian (Norton et al, 1988; Subías and Arillo, 2002). Regarding the oribatid fossil record, an outstanding upper Albian amber outcrop is San Just

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