taxonID	type	description	language	source
03B3BB0AFFA1AA531E9CFBE2FC18FDE8.taxon	diagnosis	Diagnosis. Carapace of various outlines. Umbo small, there are no special structures like spikes, nodules, gland or muscle scars. Growth lines have no reverse curvature at the anterior or posterior dorsal margins. There is no serration structure at the dorsal margin. Growth bands are ornamented with linear ornamentation, and / or from which derived decoration, like dendritic, plaid, chain-like, pitted, mixed decoration.	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA1AA531E9CFBE2FC18FDE8.taxon	discussion	Remarks. Zhang & Chen (in Zhang et al., 1976) named the superfamily Estheriteoidea. The above summarized diagnosis is a translation from the original Chinese diagnosis.	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA1AA501D3EFD8BFD38FD2F.taxon	diagnosis	Emended diagnosis. Carapaces are ovate, elliptical, rounded, or subquadrate in outline. Umbo bulging, located in the middle or anterior part of the dorsal margin. Growth lines are prominent, with serrated lower margins. Growth bands ornamented with radial lirae, which transition through reticulation to chain-like decoration. The grid arrangement is very regular, with dense chains perpendicular to the growth line. The longitudinal mesh wall is thickened and the mesh becomes narrower and longer, like the chain hole, which becomes a regular, radially arranged discontinuous linear structure on an external mould. Growth bands in the umbonal area ornamented with widely spaced radial lirae, between which short lirae and crossbars occur, and forming fine reticulation. Puncta occur between radial lirae and within reticulation.	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA1AA501D3EFD8BFD38FD2F.taxon	discussion	Remarks. This family was named by Zhang & Chen (in Zhang et al., 1976) to include Halysestheria Zhang & Chen in Zhang et al., 1976, Brachygrapta Novozhilov, 1954, Pseudocyclograpta Chang, 1957, Tylestheria Zhang & Chen in Zhang et al., 1976, Aglestheria Chen in Zhang et al., 1976. Later, Dictyestheria Chang & Chen, 1964 and Plectestheria Zhang & Chen in Zhang et al., 1976 were assigned to this family by Li et al. (2009).	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA2AA501E9CFD4BFD2BF88D.taxon	diagnosis	Emended diagnosis. Carapace moderate in size; elliptical, oval, circular or subquadrate in outline; umbo anterior or subcentral; growth lines with serrated lower margins; growth bands in umbonal area of the carapace ornamented by long radial lirae that are relatively widely spaced with an intercalated fine reticulation; those on ventral part of carapace ornamented by dense radial lirae that are separated by cross-bars to form chain-like ornament, which appears as radially aligned, discontinuous, short, fine ridges on the external mould (Li et al., 2009).	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA2AA501E9CFD4BFD2BF88D.taxon	distribution	Locality and horizon. Heilongjiang and Jilin provinces, Inner Mongolia, northeastern China, First Member of the Nenjiang Formation; Yunnan Province, southwest China, the Luojumei Member (the lowest member) of the Jiangdihe Formation; upper Santonian.	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA2AA501E9CFD4BFD2BF88D.taxon	discussion	Remarks. Intheoriginaldescriptionof Halysestheria, Zhang & Chen (in Zhang et al., 1976) overlooked the puncta on growth bands and the serration along the lower margins of growth lines, which were first seen by Li (2005) in specimens of Halysestheria yui (Chang, 1957) from the Upper Cretaceous Taipinglinchang Formation along the Heilongjiang river in northern Heilongjiang Province. These features were also discovered in specimens from the First Member of the Upper Cretaceous Nenjiang Formation in Yaojia, Jilin Province (Li et al., 2009).	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA2AA551E9CF8AAFF05FEDE.taxon	description	(Figs 2 – 5) 1976 Halysestheria biformis Zhang & Chen in Zhang et al., p. 211, pl. 91, figs 1 – 2; pl. 92, figs 1 – 4; pl. 93, fig. 8. 1985 Halysestheria biformis Zhang & Chen (in Zhang et al., 1976), Chen & Shen, p. 133, pl. 13, figs 1 – 2.	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA2AA551E9CF8AAFF05FEDE.taxon	diagnosis	Emended diagnosis. Carapace moderate in size; elliptical, long oval or subquadrate in outline; umbo located in the anterior part of the dorsal margin. Growth lines are serrated in the lower margins. Growth bands in the umbonal area ornamented with widely spaced radial lirae, intercalated with fine reticulation and puncta; growth bands in the ventral part of the carapace ornamented with chain-like reticulation, which appears as radially aligned, discontinuous, short, fine ridges on external mould. Locality and horizon. Jilin Province, and Ganhe, OroqenAutonomous Banner, Inner Mongolia, northeastern China; First Member of the Upper Cretaceous Nenjiang Formation.	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA2AA551E9CF8AAFF05FEDE.taxon	description	Description. Carapace moderate in size, elliptical, long oval, or subquadrate in outline. Anterior margin widely rounded, posterior margin pointed. Umbo located in the anterior part of the dorsal margin. Growth lines prominent, 20 – 30 or more in number, serrated along their lower margins (Figs 2 E, 3 B, E, G, 4 A). Growth bands narrow in the umbonal area, become wider in the middle part of the carapace (Figs 2 A, 5 E – H); those in the ventral part of the carapace become narrower again. Growth bands near the umbo ornamented with widely spaced long radial lirae, which are simple or branched, intercalated with fine reticulation, puncta occur within the fine mesh (Figs 2 B, 3 C). Growth bands in the ventral part of the carapace, radial lirae are thickened, fine mesh between the lirae are radially aligned to form chain-like ornamentation (Figs 2 F, 3 H, 4 D, F, H), which appears as radially aligned, discontinuous, short, fine ridges on external mould (Figs 2 E, 3 G, 4 C, E, G). Growth bands in the antero-ventral part of the carapace are almost smooth with some pits in the lower part of each band (Fig. 3 F). Dimensions. In order: specimen no., number of growth bands, length (mm), height (mm), height / length ratio: NIGP 27106, 26, 6.8, 4.6, 0.67; NIGP 174748, 31,8.4, 5.9, 0.71; NIGP 174749, 33, 7.7, 5.3, 0.7; NIGP 174750, 25, 8.5, 5.9, 0.69; NIGP 174751, 21, 7.8, 5.2, 0.67; NIGP 174752,> 14, 9.2, 6.8, 0.74; NIGP 174753, 34, 7.5, 4.7, 0.63; NIGP 174754,> 21, 7.3, 4.6, 0.64; NIGP 174755, 26, 7.0, 4.3, 0.61; NIGP 174756, 25, 7.6, 5.1, 0.66; NIGP 174757, 22, 7.7, 4.6, 0.60.	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
03B3BB0AFFA2AA551E9CF8AAFF05FEDE.taxon	discussion	Remarks. In order to make a comparison, the holotype specimen of the type species (an external mould of a right valve) was also examined under the SEM (Fig. 2 B – F). Although the specimen was varnished in order to protect it, clear micrographs have been taken from growth bands near the umbo (Fig. 2 B, D) and in the ventral part of the carapace external mould (Fig. 2 E). Clear widely spaced radial lirae with intercalated reticulation and puncta in the dorsal part of the carapace, and a chain-like ornamentation occurs on growth bands in the ventral part of the carapace. The specimens from Inner Mongolia have elliptical, long oval or subquadrate outline, the height / length ratio between 0.61 and 0.74. In consideration of the sex dimorphism, the long oval form may be male, and subquadrate form may be female. Except for the type species, several other species have also been described from the First Member of the Nenjiang Formation, such as Halysestheria ovata (Chang, 1957), H. qinggangensis Chen in Zhang et al., 1976, H. rhombica Zhang & Chen in Zhang et al., 1976, H.? sublineata Zhang & Chen in Zhang et al., 1976, H. subquadrata Zhang & Chen in Zhang et al., 1976, H. subtermina (Chang, 1957), H. yui (Chang, 1957). Li (2005) considered that H. qinggangensis and H. subtermina are junior synonyms of H. yui, the former two species have an elliptical carapace, and H. yui has a rounded carapace. The rounded carapace may be female, and the elliptical carapace may represent the male. While the H.? sublineata, having a long oval carapace, was named basing on only one specimen. It could be a junior synonym of the type species. H. subquadrata has a subquadrate carapace, which associates with H. yui, H. ovata and H. subtermina (Zhang et al., 1976), thus, may be they are the same species. H. rhombica is similar with the type species, and was named basing on only one broken specimen. It could be a junior synonym of the type species.	en	LI, GANG (2021): Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China. Palaeoentomology 4 (2): 156-164, DOI: 10.11646/palaeoentomology.4.2.4, URL: http://dx.doi.org/10.11646/palaeoentomology.4.2.4
