中国科学院南京地质古生物研究所机构知识库

Early Cretaceous plants are widely distributed in a number of localities and horizons in the Tetori Group in central Japan. However, the stratigraphical occurrences and diversity patterns of some plant groups and their palaeoclimatic implications are not well understood. In this study, we report the diverse fossil plants recently collected from the Lower Cretaceous Itsuki and Nochino formations of the Tetori Group in the Kuzuryu area, central Japan. The plant assemblage from the lower and middle part of the Itsuki Formation has no Ryoseki-type floral element, whereas the assemblage from the Nochino Formation has some Ryoseki-type floral elements such as microphyllous conifers. The occurrence of Ryoseki-type floral elements is consistent with floral change that conifers are more diverse in the Nochino Formation than in the Itsuki Formation, and a warming and drying climate trend from the Itsuki Formation to the Nochino Formation is recognized. The Early Cretaceous warming and drying trend recorded in floral assemblages of the Tetori Group is considered to reflect the paleoclimate transition represented by drastic shrinking of the Hadley circulation in the mid-latitudes of East Asia, thus providing evidence for understanding the climatic switch pattern during the Early Cretaceous. (C) 2019 Published by Elsevier Ltd.