CHARACTERISTICS OF OSTRACODA FOSSIL ASSEMBLAGE OF THE LOWER CRETACEOUS DALAZI FORMATION IN JIAOHE BASIN, JILIN PROVINCE

The Lower Cretaceous Dalazi Formation is widely developed in Jiaohe Basin, with ostracoda, conchostraca and plant debris fossils occurred near Baojia village. Through the stratified fossil collection in 1:2 000 surveyed geological section, 5 genera with 9 species of ostracoda are discovered from Daliazi Formation at the section on the north of Baojia village, including 1 similar species and 6 undefined species: Cypridea paracavernosa, C. concinaformis, C. sp., Candoniella cf. candida, Candoniella sp., Scabriculocypris sp., Mongolianella sp., Candona sp. 1 and Candona sp. 2, respectively. Combined with previous fossil findings, the Cypridea paracavernosa-C. concinaformis assemblage is established, which could be compared with the ostracoda of Daliazi Formation in Yanbian, Jilin Province, and the age was probably the late Early Cretaceous.