Abstract:

The Jiayin area of Heilongjiang Province is the first fossil dinosaur locality in China. Many fossils have been found from this area but lacking reasonable explanation to the living environment and extinction causes of the dinosaurs. The Late Cretaceous dinosaur-bearing strata have been divided in ascending order as the Yong'an, Taipinglinchang, Yuliangzi and Furao formations. The strata contain abundant dinosaurs and sporopollen fossils, and the Polypodiaceaesporites-Monosulcites-Beaupreaidites, Cyathidites-Taxodiaceaepollenites-Aguilapollenites and Classopollis-Ephedripites-Sphagnumsporites assemblages have been recognized. The fossil assemblages and sedimentary records show that the Jiayin area was generally in subtropical climate during Late Cretaceous. The assemblage variation of spore and pollen indicates a change from warm humid to dry hot climates. Abundance of salt-alkaline megatherm Classopollis-Ephedripites assemblage in a limited time illustrates a short duration of dry hot climate by latest Cretaceous. Such extreme climatic change and ecologic overturn are possible causes of the dinosaur extinction in the study area. Other factors, such as asteroid impact and large volcanic eruption triggering global mass extinction caused the regional climate change.

Key words: Jiayin in Heilongjiang, Late Cretaceous, spore and pollen, climate change, dinosaur extinction