ÔØ ÅÒÙ×Ö ÔØ

Late Pliocene Smilax (Smilacaceae) leaves from Southwest China: Phytogeo- graphical and paleoecological implications

Jing-Yu Wu, Yu-Sheng (Christopher) Liu, Su-Ting Ding, Jun Li, Peng- Cheng An

PII: S0034-6667(16)30158-0 DOI: doi:10.1016/j.revpalbo.2017.02.006 Reference: PALBO 3841

To appear in: Review of Palaeobotany and Palynology

Received date: 26 August 2016 Revised date: 19 February 2017 Accepted date: 20 February 2017

Please cite this article as: Wu, Jing-Yu, Liu, Yu-Sheng (Christopher), Ding, Su-Ting, Li, Jun, An, Peng-Cheng, Late Pliocene Smilax (Smilacaceae) leaves from Southwest China: Phytogeographical and paleoecological implications, Review of Palaeobotany and Palynology (2017), doi:10.1016/j.revpalbo.2017.02.006

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT

Late Pliocene Smilax (Smilacaceae) leaves from Southwest China:

phytogeographical and paleoecological implications

Jing-Yu Wua,b*, Yu-Sheng (Christopher) Liuc, Su-Ting Dinga,b, Jun Lia, Peng-Cheng Ana a Key Laboratory of Mineral Resources in Western China (Gansu Province), School of Earth Sciences, and

College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China b State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology,

Chinese Academy of Sciences, Nanjing 210008, China cOffice of Research and Graduate Studies, Prairie View A & M University, Prairie View, TX 77446, USA

*Correspondence (Email: [email protected]).

Abstract

Abundant fossil records indicate that the genus Smilax L. was widely distributed in North America and

Europe during the Paleogene and thrived in the Miocene. However, since the early Pliocene, the fossil occurrence of Smilax has become very rare. In this study, we describe three leaf taxa of Smilax from the upper Pliocene of West Yunnan, Southwest China based on their leaf architecture and cuticle features.

Smilax tengchongensis sp. nov. and S. cf. bracteata Presl differ from each other both in leaf shape and cuticle features. The leaves of Smilax sp. possess a different shape and venation but share similar cuticle ACCEPTED MANUSCRIPT features with those of S. tengchongensis sp. nov. The morphological diversity of our fossils indicates that a warm and humid climate with a multilayered structure existed in the Pliocene forests of West Yunnan.

Moreover, recent molecular studies indicate that both New World and Old World species of Smilax exhibited an intercontinental disjunct distribution via the Beringia land bridge between East Asia and North

America. However, this biogeographic disjunction is not well demonstrated by the fossil records as a result of inadequate paleobotanical data.

Keywords: Smilax fossils, cuticle, Pliocene, biogeography, Southwest China