It is appropriate to ascribing the Nenjiang Formation in Songliao Basin to the early Late Cretaceous time.The main evidence is that the Nenjiang Forma-tion contains Talicypridea

the typical fossil of the Late Cretaceous

which often coexisted with Dinosaur eggs typical also of the Late Cretaceous.Further-more

the Cypridea(Pseudocypridina)and the Cypridea cavernosa are quite com-mon in this formation.Apart from that

it contains some Cenozoic compo-nent such as Candona

Condoniella and Eucypris.The feature of Ostracoda are quite similar to those in the overlying Upper Cretaceous Sifanstai and Ming-shui Formations.