The Dawenkou Basin is a Cenozoic terrestrial fault basin in Shandong Province, East China, containing abundant mineral resources, especially gypsum. Recently a borehole was drilled in this basin unearthing the upper and middle members of the Dawenkou Formation. From the upper member, well-preserved ostracodes were discovered, which are entirely non-marine taxa including species of Eucypris, Caspiolla, Candona and Candoniella. Based on the new material, a new species Candona dawenkouensis n. sp. was erected. The ostracode assemblage biostratigraphically indicates an age of middle Eocene to Oligocene of the upper member of the Dawenkou Formation and the strata bearing mineral resources (mainly gypsum) of the middle member of the Dawenkou Formation is likely early Eocene.

大汶口盆地是我国东部山东省的一个新生代陆相断陷盆地，矿产资源特别丰富，尤其是石膏。最近在该盆地钻探了一个钻孔，发现了大汶口组的上段和中段。在上段，发现了保存完好的介形类动物，它们完全是非海洋类群，包括桉属、卡斯皮奥拉属、坎多纳属和坎多尼属属。基于新材料，大汶口坎多纳新种n. sp。被竖立起来。介导组合生物地层表明大汶口组上段为中始新世至渐新世，大汶口组中段含矿产资源（主要为石膏）的地层可能为早始新世。