FIGURE 2 in Taxonomy of the clam shrimp Halysestheriidae (Diplostraca: Spinicaudata) from the Upper Cretaceous Nenjiang Formation in central Dayangshu Basin of eastern Inner Mongolia, northeastern China

FIGURE 2. Halysestheria biformis Zhang & Chen in Zhang et al., 1976 emend. All are SEM images except A, which is a light micrograph. The specimen was collected from the First Member of the Upper Cretaceous Nenjiang Formation in Jilin, northeastern China. A, An external mould of a right valve, holotype NIGP27106. B, The furrows intercalated nodular platform on a growth band near the umbo. C, A reverse image of B, widely spaced radial lirae with intercalated reticulation and puncta, lirae simple or branched. D, Widely spaced furrow with intercalated nodular platform on growth bands near the umbo. E, Radially aligned, discontinuous short ridges or nodules on growth bands in the ventral part of the carapace external mould, and serration along the lower margins of growth lines. F, A reverse image of E, showing the dense radial lirae with intercalated chain-like ornamentation on growth bands in the ventral part of the carapace, growth lines with serrated lower margins. Scale bars are 1 mm in A; 20 µm in B, C; 100 µm in D–F.