J Syst Evol ›› 2020, Vol. 58 ›› Issue (1): 89-100.DOI: 10.1111/jse.12480

• Research Articles • Previous Articles     Next Articles

Mummified Magnoliaceae woods from the upper Oligocene of South China, with biogeography, paleoecology, and wood trait evolution implications

Lu-Liang Huang1,2, Jian-Hua Jin1*, Cheng Quan3,*, and Alexei A. Oskolski2,4,5   

  1. 1State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources, and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
    2State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
    3School of Earth Science and Resources, Chang’an University, Xi’an 710054, China
    4Department of Botany and Plant Biotechnology, University of Johannesburg, Johannesburg 2006, South Africa
    5Komarov Botanical Institute of the Russian Academy of Sciences, St. Petersburg 197376, Russia
  • Received:2018-09-26 Accepted:2019-01-01 Online:2019-04-07 Published:2020-01-01

Abstract: In this paper, we describe a new species Magnolia nanningensis sp. nov., based on exceptionally well‐preserved mummified fossil woods from the late Oligocene of the Nanning Basin, Guangxi, South China. The features of these woods indicate a close affinity to the section Michelia of the subgenus Yulania belonging to the genus Magnolia sensu lato (Magnoliaceae). Magnolia nanningensis is the first fossil record of the section Michelia from China, the modern diversity center of this group. These mummified woods provide fossil evidence supporting molecular dating that estimated an Oligocene age for divergence of the tropical evergreen section Michelia and the temperate deciduous section Yulania. Helical thickenings on vessel walls and a high degree of vessel grouping found in these fossil woods could be adaptive to temporary, possibly seasonal, droughts and, as suggested by other woods from the Nanning Basin, could be indicative of a monsoon‐influenced tropical climate in Guangxi during the late Oligocene. Helical thickenings have not been reported in magnoliaceous fossil woods prior to the Oligocene. The appearance of this trait was presumably a response to abrupt climate cooling near the Eocene–Oligocene boundary, followed by increase in climate seasonality. The associated increase of latitudinal zonation might be a possible trigger for divergence between the tropical evergreen sect. Michelia and the temperate deciduous sect. Yulania.

Key words: evolution, late Oligocene, Magnoliaceae, mummified wood, palaeoecology, South China