Abstract Detail

Paleobotany

Huang, Luliang [1], Jin, Jianhua [1], Quan, Cheng [2], Oskolski, Alexei [3].

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

Mummified fossils are extraordinarily important for understanding both biotic evolution and ecology in geological time, by uniquely providing a far more detailed source of information in comparison to impression or even permineralized materials. In this paper, we describe a new species of Magnolia, 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). This 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 may be adaptative to temporary, possibly seasonal, droughts and, as suggested by other woods from the Nanning Basin, may 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 and 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.

1 - Sun Yat-sen University, School Of Life Sciences, 135 Xingangxi Road, Guangzhou, Guangdong, 510275, China
2 - Chang'an University, School of Earth Science and Resources, 126 Yanta Road, Xian, Shanxi, 710054, China
3 - Botanical Museum, Prof Popov Str. 2, St. Petersburg, 197376, Russian Federation

Keywords:
evolution
late Oligocene
Magnoliaceae
mummified wood
palaeoecology
South China.

Presentation Type: Oral Paper
Session: PAL4, Paleobotany IV: Paleogene Paleobotany
Location: Tucson C/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 5:00 PM
Number: PAL4006
Abstract ID:102
Candidate for Awards:None