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

This dataset contains source image stacks for the paper <br>Oldest determined record of a mesostigmatic mite (Acari: Mesostigmata: Sejida) in Cretaceous Burmese amberby OMID JOHARCHI, DMITRY VORONTSOV and DAVID EVANS WALTER<br>The 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.<br><br>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.<br>Images are stored as JPEG files in ZIP archives. Each archive corresponds to one stack. <br>Already focus-stacked images are stored as JPEG.Scalebars in a separate ZIP archive. <br>

本数据集包含论文《白垩纪缅甸琥珀中已知最古老的中气门螨（蜱螨亚纲（Acari）：中气门目（Mesostigmata）：Sejida）记录》[作者：OMID JOHARCHI、DMITRY VORONTSOV与DAVID EVANS WALTER]的源图像堆栈。
该论文基于第二若螨（deutonymphs），首次报道了缅甸琥珀中Sejida（=Sejina）下目Sejidae科（总科Sejoidea）类群。该琥珀标本中同时伴生有膜翅目（Hymenoptera）青蜂科（Scelionidae）寄生蜂、双翅目（Diptera）蠓科（Ceratopogonidae）蝇类以及缨翅目（Thysanoptera）Adiheterothripidae科蓟马。该记录将Sejida（=Sejina）的演化时间追溯至白垩纪中期（约1亿年前），不仅是中气门目（Mesostigmata）已知最古老的有效记录，同时也是整个寄生形类（Parasitiformes）支系中最古老的类群记录之一。
为完成该螨类标本的成像工作，研究团队使用了两类显微镜：其一为配备水浸物镜（40倍、60倍）及油浸物镜（100倍）的尼康（Nikon）E-800正置显微镜；其二为配备油浸物镜（100倍）的蔡司（Zeiss）AxioImager A2正置显微镜，成像方式采用明场照明与微分干涉差（DIC）技术。为实现琥珀标本内部更深层区域的成像，研究团队除采用常规的盖玻片分隔浸油成像技术外，还参照Khaustov等人（2021）的方法，使用了饱和果糖溶液进行成像。图像堆栈（单堆栈最多包含200个焦平面）通过奥林巴斯（Olympus）OM-D E-M10-II数码相机采集获得。
图像以JPEG格式存储于ZIP压缩包中，每个压缩包对应一个图像堆栈。已完成焦点堆叠的图像同样以JPEG格式存储，比例尺文件则单独打包于一个ZIP压缩包中。