Fossil mesostigmatic mite (Acari: Mesostigmata: Sejida) from Cretaceous Burmese amber

This dataset contains source image stacks for the paper Oldest determined record of a mesostigmatic mite (Acari: Mesostigmata: Sejida) in Cretaceous Burmese amberby OMID JOHARCHI, DMITRY VORONTSOV and DAVID EVANS WALTERThe paper describes the first record of the Sejida (= Sejina) family Sejidae (superfamily Sejoidea) from Burmese amber, based on deutonymphs. Specimens have been found in the amber piece along with a wasp (Hymenoptera: Scelionidae), flies (Diptera: Ceratopogonidae) and thrips (Thysanoptera: Adiheterothripidae). This record traces the Sejida (= Sejina) back to the mid-Cretaceous (ca. 100 Ma) and represents not only the oldest valid record of Mesostigmata, but it is also one of the oldest examples of the entire Parasitiformes clade.To image the mites compound microscopes Nikon E-800 with water (40x and 60x) and oil (100x) immersion optics and Zeiss AxioImager A2 with oil immersion optics (100x) were used, with brightfield illumination and differential interference contrast. To image deeper into the piece, in addition to standard technique with immersion oil separated from the amber by a coverslip, we used a saturated fructose solution, as described in Khaustov et al. (2021). Stacks of images, comprising multiple focal planes (up to 200 in a single stack), were obtained with Olympus OM-D E-M10-II digital camera.Images are stored as JPEG files in ZIP archives. Each archive corresponds to one stack. Already focus-stacked images are stored as JPEG.Scalebars in a separate ZIP archive.