Northern Hemisphere megafossil of Dacrycarpus (Podocarpaceae) from Miocene of South China and its evolutionary and palaeoecological implication
Northern Hemisphere megafossil of Dacrycarpus (Podocarpaceae) from Miocene of South China and its evolutionary and palaeoecological implication
复制标题
华南中新世北半球罗汉松科巨型化石及其演化和古生态意义
DOI：
10.1111/jse.12534
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发表时间：
2019
影响因子：
3.7
通讯作者：
Jin J. H.
中科院分区：
文献类型：
--
作者：
Wu X. K.;Zavialova N. E.;Kodrul T. M.;Liu X. Y.;Gordenko N. V.;Maslova N. P.;Quan C.;Jin J. H.
现代属Dacrycarpus（Endl.）de Laub。罗汉松科共有9种，主要分布于太平洋西南部的热带山地雨林，范围从新西兰到低纬度的亚洲。该属在两个半球都有丰富的化石记录，但所有已知的巨型化石都仅限于澳大拉西亚和南美洲。在此报道了广东产的Dacrycarpus guipingensissp. nov.产于广西中新统二字塘组。这是北方第一个大的珊瑚化石群。新种的特征是叶的二形木乃伊化，茎生胚珠，花粉内有雄球花。它类似于外展的Dacrycarpus imbricatus（Blume）de Laub.，这在中国南部和缅甸北方到斐济的热带雨林中很常见。本文首次用CT扫描和透射电镜观察了一种化石材料中的Dacrycarpus原位花粉粒的种球解剖结构和外壁超微结构。为了比较的目的，花粉形态和超微结构的数据，现代D。imbricatusfor the first time. D. Guipingens化石有力地表明Dacrycarpus从南半球中新世到达亚洲。基于现代生态位和相关化石元素，该化石地点可能在中新世被针叶阔叶山地雨林覆盖。
The modern genusDacrycarpus(Endl.) de Laub. of the family Podocarpaceae, containing nine species, is mainly distributed in tropical mountain rainforests of the southwestern Pacific region, ranging from New Zealand to low‐latitude Asia. This genus has abundant fossil records in both hemispheres, but all the known megafossils were limited to Australasia and South America. Here we report onDacrycarpus guipingensissp. nov. from the Miocene Erzitang Formation of Guangxi, South China. This is the first megafossil ofDacrycarpusin the Northern Hemisphere. The new species is represented by mummified dimorphic foliage, ovuliferous shoots, and a male cone within situpollen. It resembles the extantDacrycarpus imbricatus(Blume) de Laub., which is common in rainforests from southern China and northern Myanmar to Fiji. This paper presents the first data on the anatomical structure of seed cone and exine ultrastructure ofDacrycarpus in situpollen grains from a fossil material by using computed tomography scanning and ultrathin sectioning. For comparative purpose, data on the pollen morphology and ultrastructure were obtained for modernD. imbricatusfor the first time. TheD. guipingensisfossils strongly suggest the Miocene arrival ofDacrycarpusin Asia from the Southern Hemisphere. Based on the modern ecological niche and related fossil elements, this fossil locality was probably covered by conifer–broad‐leaved mountain rainforests during the Miocene.