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Taxonomy from Fossilworks.com. Etymology: “Jehol,” refers to “the Jehol Biota”; “chelys” is “turtle” in Greek; the specific epithet refers to the type locality. Diagnosis from Shao et al. 2018, p. 7/21: "This new taxon has a low-domed shell, as in other Cretaceous sinemydids, and it is diagnosted with an unusual combination of features: nasal absent; midline contact of prefrontals; interorbital roof narrow; parietal expanded bilaterally along the supraoccipital crest; parietal separated from squamosal; supraoccipital crest slightly longer than squamosal horn; upper temporal emargination moderately developed; cranial scales present; oval carapace distinctly longer than wide; nuchal emargination shallow; preneural absent; eight neurals; two subequal suprapygals; pygal present; third costals with parallel anterior and posterior sides; cervical scale present; vertebral scales wider than long; first vertebral wider than nuchal and contact second marginal; central and posterior plastral fenestrae absent; lateral plastral fenestrae large; four phalanges of pedal digit V." Line drawings from Shao et al. 2018 p. 4 and 6: Scale bar equals 50mm References: Shao et al. (2018), Hyperphalangy in a new sinemydid turtle from the Early Cretaceous Jehol Biota. PeerJ 6:e5371; DOI 10.7717/peerj.5371 Zhiqiang Yu, Min Wang, Youjuan Li, Chenglong Deng, Huaiyu He (2021) New geochronological constraints for the Lower Cretaceous Jiufotang Formation in Jianchang Basin, NE China, and their implications for the late Jehol Biota, Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 583, 110657, ISSN 0031-0182, https://doi.org/10.1016/j.palaeo.2021.110657. GAO Fu-liang, JIANG Yang, PAN Yu-qi, WANG Xuan, WU Zi-jie, FAN Shuo, DAI De-yu (2018) DIVISION AND SIGNIFICANCE OF THE PRECIOUS FOSSIL-BEARING BEDS OF JIUFOTANG FORMATION IN SIHEDANG AREA, LIAONING PROVINCE[J]. Geology and Resources, 27(6): 503-507.

Taxonomy from Fossilworks.org. The name "Jehol Biota" replaced the former "Jehol Fauna", which Amadeus William Grabau (1923) defined as the fossil assemblage typified by numerous fossils of the conchostracan Eosestheria, the mayfly Ephemeropsis, and the Teleost fish Lycoptera. Thus it was sometimes called "EEL". Ephemeropsis trisetalis is a mayfly nymph described by Eichwald in 1864. the type locality is Tourga river in siberia, an Aptian lacustrine mudstone in the Turga Formation of the Russian Federation. Some Chinese paleoentomologists attributed most of the specimens of Hexagenitidae, which are similar to Ephemeropsis from China, especially Northern China, to so-called Ephemeropsis trisetalis Eichwald 1864. Hong (1982) published a line drawing (Fig. 8C.) of imago based on a specimen from Yixian Formation, Heishangou Village, Chifeng County, Liaoning Province, China. The line drawing shows the same character of new genus Epicharmeropsis: distinct intercary veins existing between MP1 and CuA1 which is obviously different from Ephemeropsis although the drawing itself had (according to Huang et al. 2007) some mistakes. Huang, et al. 2007 are of the opinion that the species of Ephemeropsis, which only occurred in Transbaikalia of Russia and Mongolia, was not present in China. The Ephemeropsis-like imago specimens reported before from China, which was classified as Ephemeropsis trisetalis, should be placed into the new genus Epicharmeropsis. Of course, as the nymph specimens of Hexagenitidae from China have not been described in detail and the association between nymphs and adults has not been established, their opinion should be considered as preliminary. References: Eichwald, E. (1864). Sur un terrain jurassique à poissons et insectes d'eau douce de la Sibérie orientale. Bulletin de la Société Géologique de France, Deuxième Série 21:19-25. Hong, Y. C. (1982). Mesozoic Fossil Insects of Jiuquan Basin in Gansu Province. Geological Publishing House, Beijing, 210 pp. Huang, J., Ren, D., Sinitshenkova N. D. & Shih, C. (2007). New genus and species of Hexagenitidae (Insecta: Ephemeroptera) from Yixian Formation, China. Zootaxa 1629: 39–50.

Taxonomy from Fossilworks.com Diagnosis for the genus and species from Shen Yan-bin et al. 1998, p. 3. “ Carapace with shallow smooth ‘optical‘ grooves and smoothly rounded lateral margins extending laterally to third thoracomere, with second thoracomere exposed via a medio-dorsal indentation; pleomeres 1-5 large, well developed and setose, with large, sub-equal, sub-rectangular protopod, ovoid endopod and ovoid, two-segmented exopod; subtriangular telson with pair of short, medial terminal spines; well-developed setose uropods with rectangular protopod, large, ovoid endopod and exopod of two subequal segments.” Line drawing from Taylor 1999, p. 49: Identified by oilshale using Shen et al. 1998 References: Shen Yan-bin, Taylor, Rod S., Schram, Frederick R. (1998). New spelaeogriphacean (Crustacea: Peracarida ) from the Upper Jurassic of China. Contributions to Zoology 68 (1) 19-36. Taylor, R. S. (1999). The fossil Crustacea of China: their taxonomy, palaeobiology, biogeography and phylogenetic relationships. Fac. der Biologie.