Leaf fossils of Sabalites (Arecaceae) from the Oligocene of northern Vietnam and their paleoclimatic implications

Ai Song; Jia Liu; Shui-Qing Liang; Truong Van Do; Hung Ba Nguyen; Wei-Yu-Dong Deng; Lin-Bo Jia; Cédric Del Rio; Gaurav Srivastava; Zhuo Feng; Zhe-Kun Zhou; Jian Huang; Tao Su

doi:10.1016/j.pld.2021.08.003

Leaf fossils of Sabalites (Arecaceae) from the Oligocene of northern Vietnam and their paleoclimatic implications

Plant Divers. 2021 Sep 3;44(4):406-416. doi: 10.1016/j.pld.2021.08.003. eCollection 2022 Jul.

Authors

Ai Song^{1

2}, Jia Liu², Shui-Qing Liang², Truong Van Do^{3

4}, Hung Ba Nguyen³, Wei-Yu-Dong Deng², Lin-Bo Jia⁵, Cédric Del Rio², Gaurav Srivastava⁶, Zhuo Feng¹, Zhe-Kun Zhou², Jian Huang², Tao Su²

Affiliations

¹ Institute of Palaeontology, Yunnan Key Laboratory for Palaeobiology, MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan Key Laboratory of Earth System Science, Yunnan University, Kunming, 650500, China.
² CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, China.
³ Vietnam National Museum of Nature, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Viet Nam.
⁴ Graduate Academy of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Viet Nam.
⁵ CAS Key Laboratory of Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650204, China.
⁶ Birbal Sahni Institute of Palaeosciences, Lucknow, 226 007, India.

Abstract

Recent paleobotanical investigations in Vietnam provide a good opportunity to improve our understanding of the biodiversity and paleoclimatic conditions in the geological past of Southeast Asia. Palms (Arecaceae) are a diverse family of typical thermophilous plants with a relatively low tolerance for freezing. In this study, we describe well-preserved fossil palm leaves from the Oligocene Dong Ho Formation of Hoanh Bo Basin, northern Vietnam. Characters of the fossil leaves, such as a fan-shaped costapalmate lamina, an unarmed petiole, a costa slightly enlarged at the base that then tapers distally into the blade, and well-preserved amphistomatic leaves with cuticles, suggest that they represent a new fossil species, which we herein designate Sabalites colaniae A. Song, T. Su, T. V. Do et Z.K. Zhou sp. nov. Together with other paleontological and palaeoclimatic evidence, we conclude that a warm climate prevailed in northern Vietnam and nearby areas during the Oligocene.

Keywords: Fossil; Leaf; Oligocene; Paleoclimate; Palm; Vietnam.