Cyclocypris invalida Zhang 1985

Cyclocypris invalida Zhang, 1985 Figs. 2, 5K–R. 1985 Cyclocypris invalida —Zhang: p. 67, pl. 28, figs. 13a–b, 14a–c, 15a–c. Material. Sixty-four carapaces, but most of them partially covered with sediment. 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. Remarks. The studied specimens match perfectly with the description of Cyclocypris invalida Zhang, 1985. Therefore, they are assigned to the species C. invalida. Distribution. Xiaonangou Formation (this study), and lower part of the Sunjiawan Formation (Zhang 1985).