Abstract Detail


Wang, Meiting [1], Xiao, Liang [2], Li, Xiangchuan [2], Liang, jiaqi [2], Ji, deshuang [2].

Fossil leaves and fruits of Acer from the Miocene in central Inner Mongolia.

Inner Mongolia lying on the northern of China, is characterized by a temperate arid continental climate harboring vast steppes and deserts today. The studied section, lithologically confined to the Hannuoba Formation is mainly composed of a set of grey, black and purplish grey olivine basalt, interbedded with grey marl, mudstone and black oil shale, near the Zhuozi County, central Inner Mongolia, China. Here we researched two fruits and one leaf of Acer L. from the Hanuoba Formation. Leaves smooth, undented, oblate, 5.23 cm long, 5.4 cm wide, notophyll; obtuse base angle; petiolulate, insertion located at leaf margin, middle and base width symmetrical, pinnate division, lobes triangular ovate; serrated margin, and the teeth had axes of symmetry directed at an angle to the trend of the leaf margin; apex shape straigh, with base palmate veins, main veins thicker, tapering from lower to higher. Fruit samaroid, nutlet at basal end, with a diameter of 0.71.2cm, 2.53cm long, attachment angle 20° ~ 40°, nutlet angle 10° ~ 20°.Veins numerous, about 10 in number at the base, curving inwards and irregularly. Nutlet large and thick, fusiform, 0.5-0.8cm long, contact scars 0.40.6cm. After comparison the fossil leaf and samaras with those of extant Acer and fossils previously reported, it is suggested that our fossil material is the most similar to modern Acer ginnala Maxim. Therefore, Acer fossils in the Hannuoba Formation can be identified as Acer ginnala. This is the first record in China. Acer fossils have been widely distributed throughout geological history. According to the global fossil record, the fossils of Acer were mainly distributed in the Oligocene and reached the Maximum diversity in the Miocene. Acer belongs to Aceraceae, there are about 200 species in the world. There are more than 140 species in China, which are distributed in the north and south provinces with central or western regions as the distribution center. The Acer genus contains 15 groups, A. ginnala Maxim is a plant in the Ginnla Nakai group in the Acer genus, deciduous shrubs or small trees, leaf blade long ovate or long elliptic, central lobe sharp, pointed or long and narrow lancet, petiole slender, growing within 800 meters of the jungle, mainly distributed in northwest China, North China and northeast provinces and cities, as well as Yellow River and Yangtze River basin, Eastern Siberia, Korea and Japan are also found, grows in the humid areas of temperate and subtropical climate zones. This discovery not only enriched the fossil record of the Hanuoba Formation in Inner Mongolia, but also proved that the region had a warm and humid climate during the Miocene.

1 - Yanta Campus, Chang 'an University, Yanta District, Xi 'an City, Shaanxi Province, Xi 'an, 61, 710054, China
2 - Chang'an University, School of Earth Science and Resources, Yanta Campus, Chang 'an University, Xi 'an city, Shaanxi Province, xi'an, Shaanxi, 710054, China

Hannuoba Formation
geographical distribution.

Presentation Type: Oral Paper
Number: PB3002
Abstract ID:975
Candidate for Awards:Maynard F. Moseley Award

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