The middle Miocene Fotan flora of Zhangpu County, South Fujian, China has been considered to represent tropical rainforest based on the occurrence of distinctive winged fruit fossils of the Dipterocarpaceae. However, this paleoclimatic interpretation has been challenged. In this study, we describe new tropical and subtropical elements of this flora that co-occurred with Dipterocarpaceae based on newly collected fossil leaves from the Fotan flora. The fossils were identified through detailed comparison with leaves of living plants. Six new species belonging to six different families are described: Artocarpus basirotundatus sp. nov. (Moraceae), Bauhinia fotana sp. nov. (Leguminosae), Boehmeria fujianensis sp. nov. (Urticaceae), Calophyllum striatum sp. nov. (Calophyllaceae), Flacourtia serrulata sp. nov. (Salicaceae), and Macaranga stellata sp. nov. (Euphorbiaceae). They represent the first fossil records of these genera in China, with the exception of Bauhinia. These elements provide further evidence for the recognition of tropical forest in South Fujian during the middle Miocene. They show more affinities with Indian Neogene floras than with other Chinese palaeofloras. It suggests that, during the Mid-Miocene Climatic Optimum, the border between the tropical and subtropical vegetation moved north to South Fujian. The Fotan palaeoflora is the first record of Miocene floristic affinities between Indian and South Chinese floras. In contrast, the southwestern Chinese Miocene palaeofloras have a different floristic composition without clear Indian affinities. We propose that the route of exchange between the Indian and South Chinese Miocene floras passed through South-East Asia. (C) 2015 Elsevier B.V. All rights reserved.
中国福建南部漳浦县中新世中期佛昙植物群,因发现龙脑香科特征性的翅果化石,一直被认为代表热带雨林。然而,这一古气候解读受到了质疑。在本研究中,基于新采集的佛昙植物群化石叶片,我们描述了与龙脑香科共生的该植物群中的新热带和亚热带成分。通过与现存植物叶片的详细对比对这些化石进行了鉴定。描述了分属于六个不同科的六个新物种:圆基波罗蜜(新种)(桑科)、佛昙羊蹄甲(新种)(豆科)、福建苎麻(新种)(荨麻科)、条纹红厚壳(新种)(红厚壳科)、细齿罗庚果(新种)(杨柳科)以及星毛血桐(新种)(大戟科)。除羊蹄甲属外,这些属在中国均为首次化石记录。这些成分进一步证明了中新世中期福建南部存在热带森林。与中国其他古植物群相比,它们与印度新近纪植物群的亲缘关系更为密切。这表明,在中新世气候适宜期,热带和亚热带植被的分界线北移至福建南部。佛昙古植物群是印度与中国南部植物群在中新世存在区系亲缘关系的首个记录。相比之下,中国西南部中新世古植物群具有不同的区系组成,与印度没有明显的亲缘关系。我们认为,印度与中国南部中新世植物群之间的交流路线经过东南亚。(C)2015爱思唯尔出版社保留所有权利。