taxonID	type	description	language	source
072187EE7566197247F03B36FEE7C491.taxon	type_taxon	Type species. Cypris granulosa (Sowerby, 1836) Cypridea sp.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197247F03B36FEE7C491.taxon	description	Figs. 2, 3 A – B.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197247F03B36FEE7C491.taxon	materials_examined	Material. One deformed carapace.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197247F03B36FEE7C491.taxon	discussion	Remarks. Although only a deformed carapace was found, this specimen matches the morphologic characteristics of the genus Cypridea, having a rostrum. Due to the poor preservation of the specimen, it cannot be identified to the species level.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197247F03D41FC72C540.taxon	type_taxon	Type species: Cypridea distributa Stankevitch (in Stankevitch & Sochava 1974)	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197447F03DE9FE89C373.taxon	description	Figs. 2, 3 C – O.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197447F03DE9FE89C373.taxon	etymology	Etymology. Named for the world-renowned Chinese geologist and paleontologist, Professor Jingeng Sha, in recognition of his significant contributions to our understanding of Mesozoic bivalves and the correlation of marine and non-marine Cretaceous stratigraphy. Additionally, he has been a longstanding mentor to YQW.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197447F03DE9FE89C373.taxon	materials_examined	Holotype. NIGP 206909 (Fig. 3 D – E), complete carapace, sample 2024 - XNG- 11 from the Guanghuanjie-Yumuqiaozi section of the Xiaonangou Formation, L: 1.52 mm, H: 0.90 mm, W: 0.74 mm. Paratypes. NIGP 206910 (Fig. 3 F – G), complete carapace, sample 2024 - XNG- 11 from the Guanhuanjie-Yumuqiaozi section of the Xiaonangou Formation, L: 1.46 mm, H: 0.81 mm, W: 0.62 mm; NIGP 206912 (Fig. 3 J – K), complete adult carapace, sample 2024 - XNG- 10 A from the Guanhuanjie-Yumuqiaozi section of the Xiaonangou Formation, L: 1.52 mm, H: 0.90 mm, W: 0.71 mm; NIGP 206915 (Fig. 3 N – O), complete adult carapace, sample 2024 - XNG- 11 from the Guanhuanjie-Yumuqiaozi section of the Xiaonangou Formation. Type locality. Guanhuanjie-Yumuqiaozi section of the Baishan Basin, Xiaonangou Formation, Jilin, China (41 ° 56 ' 34.4 " N, 126 ° 34 ' 18.6 " E). Type horizon. Lower part of the Guanhuanjie-Yumuqiaozi section, Xiaonangou Formation, Baishan Basin, Jilin, China. Material. More than one hundred carapaces, but most of them compressed laterally and partially covered with sediment.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197447F03DE9FE89C373.taxon	description	Dimensions. L: 1.36 – 1.52 mm, H: 0.76 – 0.96 mm, W: 0.56 – 0.80 mm.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197447F03DE9FE89C373.taxon	diagnosis	Diagnosis. A species with elongated oval shape in lateral view; both anterior and posterior margins rounded and equicurvate; ventral margin nearly parallel to dorsal margin.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197447F03DE9FE89C373.taxon	description	Description. Carapace very large size with thick shell, elongated oval shape in lateral view, elongated ovate in dorsal view. Maximum height at anterior cardinal angle, maximum length at mid-height, maximum width at 2 / 3 of length. LV> RV; LV overlapping RV along all margins except for hinge margin. Anterior margin rounded and equicurvate, anterior cardinal angle rounded but remarkable, around 130 – 145 °. Posterior margin equicurvate, posterior cardinal angle rounded, 130 – 145 °. Dorsal margin nearly straight, gently sloping towards both anterior and posterior margins. Ventral margin nearly parallel to dorsal margin, slightly convex in LV. Rostrum short but visible, strongly bending backwards, its point acute and considerably overreaching ventral margin of the RV. Alveolar notch well-developed and triangle shape, more distinct in RV. Alveolar furrow absent. Hinge margin slightly incised, forming very shallow dorsal furrow. Surface smooth.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197447F03DE9FE89C373.taxon	discussion	Remarks. Based on the very large carapace size (larger than 1.2 mm) and the development of the rostrum, the studied specimens are assigned to the genus Mongolocypris. Mongolocypris shai sp. nov. differs from other Mongolocypris species by its more visible rostrum in the RV and the ventral margin nearly parallel to the dorsal margin. Mongolocypris shai sp. nov. is the dominant species in the Xiaonangou Formation of the Baishan Basin. Cypridea (Pseudocypridina) globra Hou, 1958 as identified by Zhang (1985), differs from the original description by Hou (1958) in having a nearly straight dorsal margin and anterior and posterior margins of almost equal width, with a less pronounced backward curvature of the rostrum. However, these carapace characteristics fully match the diagnosis of M. shai sp. nov. of this study, and thus it is assigned to M. shai sp. nov. Langtonia setina rectidorsata Sylvester-Bradley, 1949 reported from Mongolia is questionably included [The genus Langtonia is considered as a synonym of Cypridea (Pseudocypridina) by Sames (2011 a)]. Although the illustrations of Mongolian specimens in Nikolaeva and Neustrueva (1999) and Neustrueva et al. (2005) show a close resemblance to M. shai sp. nov., those authors did not provide a detailed description and only illustrated the left valve. Therefore, the relationship between L. setina rectidorsata and M. shai sp. nov. requires further investigation. Mongolocypris shai sp. nov. differs from Cypridea (Pseudocypridina) limpida Zhang, 1985 [The subgenus Cypridea (Pseudocypridina) is considered as a synonym of Mongolocypris by Hou et al. (2002)] by having parallel dorsal and ventral margins with a more rounded posterior margin. Mongolocypris yanjiensis Gou, 1983 from the Albian Dalazi Formation of the Yanji Basin is similar to M. shai sp. nov., but the former features a supracurvate posterior margin and more pronounced cardinal angles.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7566197447F03DE9FE89C373.taxon	distribution	Distribution. Xiaonangou Formation (this study) and upper part of the Fuxin Formation of western Liaoning (Zhang 1985).	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7560197447F03BA6FDAEC47D.taxon	type_taxon	Type species: Cypris faba Egger, 1910	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7560197447F03CF5FAC0C6D5.taxon	description	Figs. 2, 3 P – R, 4 A – F.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7560197447F03CF5FAC0C6D5.taxon	materials_examined	Material. More than one hundred carapaces.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7560197447F03CF5FAC0C6D5.taxon	description	Dimensions. L: 0.65 – 0.74 mm, H: 0.34 – 0.40 mm, W: 0.25 – 0.31 mm. Description. Medium to large sized, elongated oval in lateral view. Maximum length at 1 / 2 of height, maximum height at 2 / 3 of length, and width at mid-length. LV larger than RV; LV overlapping RV along all margins except for dorsal margin. Anterior margin rounded and equicurvate; anterior cardinal angle rounded. Posterior margin narrower than anterior one and infracurvate; posterior cardinal angle not visible. Dorsal margin arched and gently sloping towards both anterior and posterior margins. Ventral margin nearly straight in LV, but somewhat concave in mid-length of RV. Surface smooth.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7560197447F03CF5FAC0C6D5.taxon	discussion	Remarks. The specimens studied can be attributed to L. sinuolata Zhang, 1985 based on general outline and size, LV overlapping RV along the free margin, and the dorsal margin arched with smooth surface. This species differs from L. debilis Lübimova, 1956 by having a more rounded anterior margin and cardinal angle. Distribution. Xiaonangou Formation (this study), and upper part of the Jiufotang Formation (Zhang 1985).	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197647F03B37FDFDC3ED.taxon	type_taxon	Type species: Cypris candida Müller, 1776	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197647F03C45FCA5C69D.taxon	description	Figs. 2, 4 I – R, 5 A – B.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197647F03C45FCA5C69D.taxon	description	Dimensions. L: 0.62 – 0.68 mm, H: 0.34 – 0.43 mm, W: 0.24 – 0.31 mm. Description. Medium sized, elongated oval in lateral view. Maximum length at 2 / 3 of height, maximum height at 3 / 4 of length, and maximum width slightly behind mid-length. LV larger than RV; LV overlapping RV along all margins, including hinge margin. Anterior margin narrow and slightly supracurvate; anterior cardinal angle rounded. Posterior margin broader than anterior one, strongly infracurvate; posterior cardinal angle more rounded than anterior one. Dorsal margin arched, hinge margin long and gently slopes towards anterior margin but slopes more steeply towards posterior margin. Ventral margin nearly straight in LV, but somewhat concave in mid-length of RV. Surface smooth.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197647F03C45FCA5C69D.taxon	discussion	Remarks. The general morphology of specimens in this study is well matched with Candona praevara with an elongated oval carapace shape, maximum height at 3 / 4 of length in lateral view, LV overlapping RV along all margins, and a strongly infracurvate posterior margin.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197647F03C45FCA5C69D.taxon	distribution	Distribution. Xiaonangou Formation, upper part of the Fuxin Formation in western Liaoning (Zhang 1985) and Quantou Formation of the Songliao Basin (Zhang 1987).	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197947F03F54FAF4C287.taxon	description	Figs. 2, 5 C – J.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197947F03F54FAF4C287.taxon	materials_examined	Material. Ten carapaces. Dimensions. L: 0.40 – 0.47 mm, H: 0.22 – 0.28 mm, W: 0.16 – 0.19 mm.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197947F03F54FAF4C287.taxon	description	Description. Small sized carapace with thin-shelled and a long-oval shape in lateral view. Maximum length at 1 / 2 of height, maximum height at middle of maximum length, and maximum width at mid-length. LV larger than RV; LV overlapping RV along all margins, with strong valve overlapping in ventral area. Both anterior and posterior margins equicurvate and rounded. Surface smooth.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE7562197947F03F54FAF4C287.taxon	discussion	Remarks. In China, numerous studies have classified ostracod specimens similar to the specimens of this study, characterized by a small, thin-shelled, long-oval carapace shape, with the LV overlapping RV along all margins and both anterior and posterior margins rounded, under the genus Candoniella Schneider, 1956 (e. g., Zhang 1985, 1987; Ye et al. 2002; see Hou et al. 2002 for a review). However, Danielopol et al. (2022) argue that the genus Candoniella Schneider, 1956 is an invalid genus and that it represents a taxonomic chimera, an artifact in which juveniles of species from different Candoninae genera are amalgamated into a single taxon. It implies that all described Candoniella species require a comprehensive reassessment; to address this problem, more detailed taxonomic work and a wide morphological analysis of all specimens from the genus Candoniella are required, however, is out of our topic of present work. The studied specimens may represent juvenile individuals of a certain Candoninae genus or species. However, due to the limited number of specimens and the lack of evidence for continuous morphological changes during ontogeny, they can only be identified to the family level without determining the genus and species.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE756D197947F03B12FD83C3B1.taxon	type_taxon	Type species: Cypris globosa Sars, 1863	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE756D197947F03BA1FA31C5D1.taxon	description	Figs. 2, 5 K – R.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE756D197947F03BA1FA31C5D1.taxon	materials_examined	Material. Sixty-four carapaces, but most of them partially covered with sediment.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE756D197947F03BA1FA31C5D1.taxon	description	Dimensions. L: 0.34 – 0.37 mm, H: 0.28 – 0.34 mm, W: 0.24 – 0.31 mm. Description. Very small sized carapace, short and high when seen laterally, ovate in dorsal view. Maximum length at 1 / 2 of height, maximum height at 1 / 2 of length, and maximum width at mid-length. LV larger than RV; LV overlapping RV along all margins. Posterior end broadly rounded, anterior end roundly pointed; both anterior and posterior margins equicurvate. Dorsal margin arched and gently slopes towards both anterior and posterior margins. Ventral margin convex. Surface with very shallow pits.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE756D197947F03BA1FA31C5D1.taxon	discussion	Remarks. The studied specimens match perfectly with the description of Cyclocypris invalida Zhang, 1985. Therefore, they are assigned to the species C. invalida.	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
072187EE756D197947F03BA1FA31C5D1.taxon	distribution	Distribution. Xiaonangou Formation (this study), and lower part of the Sunjiawan Formation (Zhang 1985).	en	Wang, Yaqiong (2025): First report of the non-marine ostracod fauna from the Lower Cretaceous Xiaonangou Formation of the Baishan Basin, NE China. Zootaxa 5660 (4): 560-572, DOI: 10.11646/zootaxa.5660.4.6, URL: https://doi.org/10.11646/zootaxa.5660.4.6
