Fossil Uropodella (Acari: Mesostigmata: Sejidae) from Eocene Baltic amber

Image dataset for a paper of Evert E. Lindquist and Dmitry D. Vorontsov Uropodella (Acari: Mesostigmata: Sejidae), mites unchanged from Eocene past to Holocene present The first record is presented of the sejoid genus Uropodella (family Uropodellidae, suborder Sejida) from Baltic amber, based on a well-preserved adult male. Morphologically, the specimen is as fully advanced or modern in structure as adults of the six known extant species of Uropodella. The diagnosis of the fossil in distinction to the extant species justifies naming it as a new species. This record traces the genus back to the Eocene, representing the oldest validated age for a mesostigmatan genus. A key to species of the genus Uropodella is given. Provenance and deposition. The piece of Eocene Baltic amber mined at Usedom (a Baltic Sea island in Pomerania) containing the fossil mite treated herein originates from the private Collection of Christel and Hans-Werner Hoffeins (CCHH), original collection number CCHH-354-1. The piece is transferred to the collection of the Geological-Palaeontological Museum, Leibniz Institute for the Analysis of Biodiversity Change (LIB), Hamburg, Germany, collection number GPIH 05125. Syninclusion: Acari: Acariformes, only an anterior part (gnathosoma and propodosoma) not further identifiable, in the depth of amber. For imaging, a Nikon E-800 compound microscope with dry (10x) and water (40x and 60x) objectives was used. As the body of the mite was mostly non-translucent, most of the micrographs were made in reflected light that limited the resolution. Stacks of images, comprising multiple focal planes, were obtained with an Olympus OM-D E-M10-II digital camera. Final images were focus-stacked using Helicon Focus Pro 7.6.