Asclepiadospermum Gen. Nov., the Earliest Fossil Record Of
RESEARCH ARTICLE Asclepiadospermum gen. nov., the earliest fossil record of Asclepiadoideae (Apocynaceae) from the early Eocene of central Qinghai-Tibetan Plateau, and its biogeographic implications Cédric Del Rio1,2, Teng-Xiang Wang1,3, Jia Liu1,2, Shui-Qing Liang1,4, Robert A. Spicer1,5, Fei-Xiang Wu6, Zhe-Kun Zhou1,2,7, and Tao Su1,2,3,8 Manuscript received 29 September 2019; revision accepted 18 PREMISE: Apocynaceae is common in the fossil record, especially as seed remains from the November 2019. Neogene of Europe and North America, but rare in Asia. Intrafamilial assignment is difficult 1 CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna due to the lack of diagnostic characters, and new fossil and modern data are needed to Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, understand the paleobiogeography of this group. Yunnan 666303, China 2 Center of Conservation Biology / Economic Botany / Plant METHODS: We studied three Apocynaceae seed impressions from the Lower Eocene Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Niubao Formation, Jianglang village, Bangor County, central Qinghai-Tibetan Plateau. Mengla 666303, China Morphological data from living and fossil species were phylogenetically mapped to enable 3 University of Chinese Academy of Sciences, Beijing 100049, China systematic assignment. 4 Public Technology Service Center, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan RESULTS: We describe a new genus, Asclepiadospermum gen. nov., and two new species, 666303, China A. marginatum sp. nov. and A. ellipticum sp. nov. These species are characterized by an 5 School of Environment, Earth and Ecosystem Sciences, The Open elliptical seed, a margin surrounding the central part of the seed, and polygonal, irregular, University, Milton Keynes MK7 6AA, UK and small epidermal cells, and differ mainly in terms of the size of the margin and the 6 Key Laboratory of Vertebrate Evolution and Human shape of the apex.
[Show full text]