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 <em>Uropodella</em> (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 <em>Uropodella</em>. 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 <em>Uropodella</em> is given. <em>Provenance and deposition.</em> 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.

埃弗特·E·林德奎斯特（Evert E. Lindquist）与德米特里·D·沃龙佐夫（Dmitry D. Vorontsov）论文配套图像数据集：《<em>Uropodella</em>（蜱螨亚纲Acari：中气门目Mesostigmata：绥螨科Sejidae）：自始新世（Eocene）至全新世（Holocene）未发生形态演化的革螨》
本研究首次报道了产自波罗的海琥珀（Baltic amber）的绥螨类<em>Uropodella</em>属（尾足螨科Uropodellidae，绥螨亚目Sejida）化石，标本为保存完好的成年雄螨。形态学分析表明，该化石标本的结构与已知6种现生<em>Uropodella</em>属成螨完全一致，无演化差异。基于该化石与现生类群的形态鉴别特征，本研究将其定为新种。该记录将<em>Uropodella</em>属的起源追溯至始新世，是中气门螨类已知属级类群中经验证的最古老化石记录。本研究提供了<em>Uropodella</em>属的物种检索表。
<em>标本来源与馆藏信息</em>
本文研究的含革螨化石的始新世波罗的海琥珀产自乌瑟多姆岛（波美拉尼亚地区的波罗的海岛屿），最初馆藏于克里斯特尔·霍芬斯与汉斯-维尔纳·霍芬斯（Christel and Hans-Werner Hoffeins）的私人收藏（CCHH），原馆藏编号为CCHH-354-1。该琥珀标本现馆藏于德国汉堡莱布尼茨生物多样性变化分析研究所（Leibniz Institute for the Analysis of Biodiversity Change, LIB）地质古生物博物馆，馆藏编号为GPIH 05125。
伴生包裹体：蜱螨亚纲Acari：螨形总目Acariformes，仅保留虫体前部（颚体gnathosoma与前足体propodosoma），因处于琥珀深处无法进一步鉴定。
成像环节采用尼康E-800正置复合显微镜，搭配干镜（10×）及水浸物镜（40×、60×）。由于该革螨虫体大部分不透明，多数显微照片采用反射光拍摄，因此分辨率受限。研究采用奥林巴斯OM-D E-M10-II数码相机拍摄多焦面图像序列。最终图像通过Helicon Focus Pro 7.6软件完成焦点堆叠合成。