古地理学报 ›› 2023, Vol. 25 ›› Issue (2): 471-484. doi: 10.7605/gdlxb.2023.02.029

• 生物古地理学及古生态学 • 上一篇    下一篇

甘肃永昌乌拉尔世Sphenopteris(楔羊齿)新记录: 兼论晚古生代Sphenopteris多样性及古地理演化*

王雪莲1, 熊聪慧2, 孙柏年2   

  1. 1 中国科学院西北生态环境资源研究院,沙漠与沙漠化重点实验室,干旱区生态安全与可持续发展重点实验室,甘肃兰州 730000;
    2 兰州大学地质科学与矿产资源学院,甘肃省西部矿产资源重点实验室,甘肃兰州 730000
  • 收稿日期:2022-12-01 修回日期:2023-01-24 出版日期:2023-04-01 发布日期:2023-04-14
  • 通讯作者: 熊聪慧,女,1986年生,博士,高级实验师,研究方向为古生代陆地维管植物多样性。E-mail: xiongch@lzu.edu.cn。
  • 作者简介:王雪莲,女,1991年生,博士,特别研究助理,研究方向为古植物学和气候环境演变。E-mail: wangxuelian@nieer.ac.cn。
  • 基金资助:
    *国家自然科学基金项目(编号: 42202029,41802008,41888101),第二次青藏高原综合科学考察研究(编号: 2019QZKK0707)和甘肃省科技计划项目(编号: 21JR7RA061,20JR10RA646)联合资助

New records of Sphenopteris from the Cisuralian of Yongchang,Gansu Province,with a discussion on diversity and palaeogeographic evolution of this genus during the Late Paleozoic

WANG Xuelian1, XIONG Conghui2, SUN Bainian2   

  1. 1 Key Laboratory of Desert and Desertification & Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;
    2 School of Earth Sciences & Key Laboratory of Mineral Resources in Western China(Gansu Province), Lanzhou University,Lanzhou 730000,China
  • Received:2022-12-01 Revised:2023-01-24 Online:2023-04-01 Published:2023-04-14
  • Contact: XIONG Conghui,born in 1986,is a senior engineer at School of Earth Sciences,Lanzhou University. Her research focuses on the diversity of Paleozoic vascular land plants. E-mail: xiongch@lzu.edu.cn.
  • About author:WANG Xuelian,born in 1991,is an assistant researcher of paleobotany and paleoenvironments,at Northwest Institute of Eco?Environment and Resources,Chinese Academy of Sciences. Her research focuses on paleobotany and climate changes. E-mail: wangxuelian@nieer.ac.cn.
  • Supported by:
    National Natural Science Foundation of China(Nos.42202029,41802008,41888101),Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0707),and the Natural Science Foundation of Gansu Province(Nos. 21JR7RA061,20JR10RA646)

摘要: Sphenopteris(楔羊齿属)叶化石在全球晚古生代地层中广泛出现,但该属的系统分类位置及演化特征仍有待深入探讨,而且只有极少数种的表皮及气孔微细构造得到揭示。笔者在甘肃永昌乌拉尔统山西组中发现了2种形态保存较好且具有角质层的楔羊齿,分别是 Sphenopteris yongchangensis sp. nov.(永昌楔羊齿—新种)和Sphenopteris nystroemii (弱楔羊齿)。前者小羽片呈扇形,基部连合,侧脉分叉1次,气孔作椭圆状且为两面生; 后者小羽片呈梭形且顶端钝圆,侧脉分叉1次并达缘,气孔分布于脉间区。经对比,文中报道的2种楔羊齿可能属皱羊齿目(Lyginopteridales)。此外,统计了Sphenopteris在晚古生代的269个化石记录,结合该属的形态学、解剖学特征和分布记录,探讨了其多样性演化和古地理分布,结果表明: 宾夕法尼亚亚纪至乌拉尔世,Sphenopteris广泛分布于全球中低纬度地区,呈现出高度变异和分化; 自晚泥盆世至二叠纪,Sphenopteris型叶化石在中国自华南向华北迁移演化,说明其多样性特征不仅与湿润气候密切相关,而且与其古地理分布相耦合。

关键词: 晚古生代, Sphenopteris, 古地理分布, 多样性

Abstract: Although Sphenopteris species were widespread in the Late Paleozoic around the world,the systematic position and evolutionary characteristics of this genus still need to be addressed,and microstructures such as epidermis and stomata have only been demonstrated in very limited species. We describe two well-preserved fossil species with microstructures from the Cisuralian Shanxi Formation(Early Permian)of Yongchang,Gansu,China,including Sphenopteris yongchangensis sp. nov. and Sphenopteris nystroemii. Pinnules of S. yongchangensis sp. nov. were fan-shaped,with their base connected,lateral veins bifurcate once,and elliptical stomata are amphistomatic. Pinnules of S. nystroemii were fusiform with round top,lateral veins bifurcate once and reach leaf margin,and its stomata were distributed in interveinal area. It is more reasonable to assign the present two species of Sphenopteris to the order Lyginopteridales by detailed comparative analyses. The diversity and palaeogeographic evolution of Sphenopteris species are then considered,based on 269 occurrence records of the genus from the Late Paleozoic,in combination with morphological and anatomical characteristics and biogeographic distribution pattern. The results show that the records of Sphenopteris were widely distributed in the middle-low latitudes worldwide from the Pennsylvania to Cisuralian,indicating high variation and differentiation of Sphenopteris-type leaves. It is speculated that Sphenopteris species migrated from South China to North China during Late Devonian to Permian,and the diversity pattern was not only closely related to humid climate,but also coupled with the palaeogeographic characteristics of this genus.

Key words: Late Paleozoic, Sphenopteris, palaeogeographic distribution, diversity

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