Acta Scientiarum Naturalium Universitatis Pekinensis ›› 2022, Vol. 58 ›› Issue (5): 861-874.DOI: 10.13209/j.0479-8023.2022.058

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A New Zosterophyllopsid Plant with Encrusted Microconchids from Lower Devonian Guijiatun Formation of Qujing, Yunnan Province

YANG Shuai1, HUANG Pu2,†, LIU Lu3, WANG Jiashu1, ZHANG Jiudong4, XUE Jinzhuang1   

  1. 1. The Key Laboratory of Orogenic Belts and Crustal Evolution (MOE), School of Earth and Space Sciences, Peking University, Beijing 100871 2. Nanjing Institute of Geology and Palaeontology, Nanjing 210008 3. Beijing Museum of Natural History, Beijing 100050 4. School of Resources and Civil Engineering, Suzhou University, Suzhou 234000
  • Received:2021-10-07 Revised:2021-11-22 Online:2022-09-20 Published:2022-09-20
  • Contact: HUANG Pu, E-mail: puhuang(at)nigpas.ac.cn

云南曲靖下泥盆统桂家屯组一种新的工蕨类植物及栖生的微螺虫

杨帅1, 黄璞2,†, 刘璐3, 王嘉树1, 张久东4, 薛进庄1   

  1. 1. 造山带与地壳演化教育部重点实验室, 北京大学地球与空间科学学院, 北京 100871 2. 中国科学院南京地质古生物研究所, 南京 210008 3. 北京自然博物馆, 北京 100050 4. 宿州学院资源与土木工程学院, 宿州 234000
  • 通讯作者: 黄璞, E-mail: puhuang(at)nigpas.ac.cn
  • 基金资助:
    国家自然科学基金(41722201, 41802003)资助 

Abstract:

A new early vascular plant is described from the Guijiatun Formation of the Guogaishan section, Qujing, Yunnan. This plant shows smooth axes; the rhizomes are characterized by multiple K- or H-shaped branchings, forming a complex branching system; the erect axes are dichotomously branched; and the sporangia are helically arranged, spoon to ovoid shaped in lateral view. The plant is small in size, with better-preserved rhizomes, while the spikes are in poor preservation and the dehiscence line of the sporangia is invisible, and thus it is tentatively designated as cf. Zosterophyllum sp. Nevertheless, the character combination of this plant is different from typical species of Zosterophyllum and other related taxa, enriching the knowledge about the morphological variations of early vascular plants and about the floral assemblages from the Guijiatun Formation. Abundant microconchids, with a diameter of ca. 0.7~2.2 mm, occur on erect axes of the plant. Microconchids are a type of extinct aquatic invertebrates, spanning from the Late Ordovician to late Middle Jurassic, and they show a spiral-shaped calcareous shell and have been found to habitually colonize on various hard substrates including plants. Our finding that microconchids settled on erect axes of cf. Zosterophyllum sp. indicates that this plant was submerged by water during its growth period, and afterwards, the microconchids and their occupied plant axes were transported and then buried.

Key words: early vascular plants, zosterophyllopsids, microconchids, Guijiatun Formation, Lower Devonian

摘要:

记述发现于云南曲靖锅盖山剖面桂家屯组的一种早期维管植物。该植物茎轴裸露, 根状茎以连续多次K型或H型分枝形成复杂的分枝系统, 直立轴呈简单的二歧式分枝, 孢子囊侧视呈匙形至卵形, 螺旋状着生于穗轴上。该植物体型较小, 保存较完整的根状茎, 但孢子囊穗的保存状况较差, 孢子囊结构不够清晰, 无明显可见的孢子囊开裂线, 因此将其暂定为cf. Zosterophyllum sp.。尽管如此, 该植物展现的性状特征不同于典型的 Zosterophyllum 及其他相关属种, 丰富了人们对早期维管植物形态变异及桂家屯组植物组合的认识。在cf. Zosterophyllum sp.的直立轴表面栖生大量微螺虫(microconchids)标本, 直径为0.7~2.2 mm。微螺虫是一种已灭绝的水生无脊椎动物, 发现于晚奥陶世到中侏罗世末期地层中, 其壳体为螺旋状的钙质管, 习惯固着在包括植物在内的各种硬质基体上。微螺虫在cf. Zosterophyllum sp.的直立轴栖生, 表明该植物在生长期间曾被水体淹没, 之后微螺虫伴随植物茎干被搬运和埋藏。

关键词: 早期维管植物, 工蕨类, 微螺虫, 桂家屯组, 下泥盆统