title: Latisemenia longshania, gen. et sp. nov., a new Late Devonian seed plant from China.
abstract: The earliest known ovules in the Late Devonian (Famennian) are borne terminally on fertile branches and are typically enclosed in a cupule. Among these ovules are some that have terete integumentary lobes with little or no fusion. Here, we report a new taxon, Latisemenia longshania, from the Famennian of South China, which bears cupulate ovules that are terminal as well as opposite on the fertile axis. Each ovule has four broad integumentary lobes, which are extensively fused to each other and also to the nucellus. The cupule is uniovulate, and the five flattened cupule segments of each terminal ovule are elongate cuneate and shorter than the ovule. Associated but not attached pinnules are laminate and Sphenopteris-like, with an entire or lobate margin. Latisemenia is the earliest known plant with ovules borne on the side of the fertile axis and may foreshadow the diverse ovule arrangements found among younger seed plant lineages that emerge in the Carboniferous. Following the telome theory, Latisemenia demonstrates derived features in both ovules and cupules, and the shape and fusion of integumentary lobes suggest effective pollination and protection to the nucellus. Along with other recent discoveries from China, Latisemenia extends the palaeogeographic range of the earliest seed plants.
authors.affiliation: Key Laboratory of Orogenic Belts and Crustal Evolution, Department of Geology, Peking University, Beijing 100871, People's Republic of China dmwang@pku.edu.cn.
authors.forename: De-Ming
authors.initials: DM
authors.lastname: Wang
authors.affiliation: Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada.
authors.forename: James F
authors.initials: JF
authors.lastname: Basinger
authors.affiliation: Key Laboratory of Orogenic Belts and Crustal Evolution, Department of Geology, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Pu
authors.initials: P
authors.lastname: Huang
authors.affiliation: Key Laboratory of Orogenic Belts and Crustal Evolution, Department of Geology, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Le
authors.initials: L
authors.lastname: Liu
authors.affiliation: Key Laboratory of Orogenic Belts and Crustal Evolution, Department of Geology, Peking University, Beijing 100871, People's Republic of China pkuxue@pku.edu.cn.
authors.forename: Jin-Zhuang
authors.initials: JZ
authors.lastname: Xue
authors.affiliation: Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, People's Republic of China.
authors.forename: Mei-Cen
authors.initials: MC
authors.lastname: Meng
authors.affiliation: Key Laboratory of Orogenic Belts and Crustal Evolution, Department of Geology, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Orogenic Belts and Crustal Evolution, Department of Geology, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Zhen-Zhen
authors.initials: ZZ
authors.lastname: Deng
mesh_terms: D002681:China; D019669:Embryophyta / Q000033:anatomy & histology* / Q000145:classification*; D005580:Fossils; D054817:Pollination; D012639:Seeds
keywords: Late Devonian; Latisemenia longshania; cupule; ovule; palaeogeography; seed plant