New fossil labidostomatids (Acari: Labidostomatidae) from eocene amber and presence of an Apustulate species in Europe

Abstract

Modern-looking labidostomatid mites were found in collections of Eocene amber from diverse origins. Six of ten specimens from Baltic amber could be unequivocally assigned to the extant genus Labidostoma Kramer, 1879. These specimens showed affinities, notably by cheliceral morphology, with the extant Holarctic subgenus Cornutella, comprising large mites that commonly inhabit superficial soil layers. However, because of the unusual position of setae la and setation of the palps, the new subgenus Pseudocornutella was proposed. The habitus of a second species (two specimens from Baltic amber) resembles that of the previously described fossil L. (N.) paleoluteum. However, because of the unequivocal absence of the paired lateral gland-like pustule, it was assigned to the apustulate genus Sellnickiella, the extant species of which show a Gondwanan distribution. This is an indication that the modern distribution of the genus Sellnickiella results from extinctions over large parts of its former range. The new species probably belongs to an extinct lineage, having a large fenestration behind the lateral eye. Two additional Baltic specimens remain identified only to the family level. We also report the first finding of Labidostomatidae from Bitterfield (Germany) amber and Rovno (Ukraine) amber. © Sidorchuk E. and Bertrand M.