| Abstract Detail
Paleobotany Xu, Shenglan [1], Kodrul, Tatiana [2], Maslova, Natalia [3], Tobias, Anna [4], Quan, Cheng [5], Jin, Jianhua [6]. Fossil fruits of Nyssa and associated fungi from the late Oligocene of South China. Nyssa Gronov. ex L. (Nyssaceae) became widely distributed in the Northern Hemisphere during the Cenozoic, then suffered wide extinctions probably because of climatic changes in the late Cenozoic and Quaternary. Extant species of Nyssa have a disjunct distribution between eastern North America, Central America, and eastern Asia.
A new species of Nyssa is defined based on fruit endocarps from the upper Oligocene Yongning Formation in Nanning Basin, South China. These unilocular endocarps have obovate, rarely elliptical outline, dorsally flattened, generally with the widest point above the midline. From five to seven longitudinal narrow grooves and as many rounded wide ridges appear on ventral surface. The dorsal midline is marked by a conspicuous longitudinal ridge. Broadly triangular germination valve with rounded lateral edges and acute apex is confined to the apical third of endocarp on dorsal side. Peripheral vascular bundles are sunken in the grooves. Locule is roughly M-shaped in transverse section. Fibrous endocarp walls are 0.5–0.9 mm thick. The fossils found in the Nanning Basin are the earliest fossil record of Nyssa in Asia.
Associated fossil ascomata on Nyssa endocarp has affinities to extant genus Amphisphaeria. Dome-shaped ascomata with rounded or oval base range from 0.5 to 0.8 mm in diameter. The ascoma height in vertical section is up to 0.6 mm. The ascomata have a single central protruding ostiolar canal with a papillar central pore up to 100 µm in diameter. Ascoma wall is up to 25 µm thick, a paraplectenchyma is formed by short-celled hyphae. Ascospores are 1-septate, ellipsoid to fusoid, tapering to the ends, slightly constricted at the septum. The spore surface is mostly finely granulate, with flattened sculpture elements. Endocarps may be released from mesocarps after the animal feeds and be available to wood-destructed amphisphaeriaceous fungi.
This work was supported by the National Natural Science Foundation of China (Nos. 41872015, 41820104002), Russian Foundation for Basic Research (Nos. 19-04-00046, NM, TK).
1 - Sun Yat-sen University, 135,Xingang Road, Haizhu Area, Guangzhou, 44, 510275, China
2 - Geological Institute, Russian Academy of Sciences, Moscow 119017, Russia
3 - Borissiak Paleontological Institute, Russian Academy of Sciences, Moscow 117647, Russia
4 - Saint-Petersburg State University, St. Petersburg 199034, Russia
5 - Chang'an University,126, Yanta Road, 710061, Xi'an, China
6 - Sun Yat-sen University, School Of Life Sciences, 135 Xingangxi Road, Guangzhou, Guangdong, 510275, China
Keywords:
Nyssa
Amphisphaeria
Late Oligocene
Nanning Basin
South China.
Presentation Type: Oral Paper
Session: PAL4, Paleobotany II: Cenozoic Paleobotany
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 1:15 PM
Number: PAL4004
Abstract ID:582
Candidate for Awards:None |
