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拟合囊蕨(Marattiopsis)是蕨类植物门中较原始的厚囊蕨纲莲座蕨目合囊蕨科的一个化石属,是中生代植物群落中的重要组成分子。由于与现生植物形态相似,部分含繁殖器官化石标本常被归入现生合囊蕨属(Marattia)。尽管Marattiopsis和Marattia的使用一直存在争议,但传统上前者多用于裸羽片标本,而实羽片标本则多使用现生属名。然而,最近分子证据表明Marattia是一个并系类群的属,原有定义有所改变,因此,仅Marattiopsis属名应该保留并使用于化石标本。中国中生代的拟合囊蕨属(合囊蕨属)植物共计9种,其时空分布显示:该属在晚三叠世出现,并且分异度达到顶峰,但仅分布于华南;早侏罗世多样性大幅降低,但产地数量略有增长,并从华南扩散到华北;中侏罗世分异度和产地数量急剧衰退,仅在东北有少量残存;晚侏罗世至整个白垩纪,完全消失。本文认为拟合囊蕨多样性变化和时空分布模式与古气候和古地理综合效应密切相关:晚三叠世至早侏罗世炎热、湿润的气候条件有利于拟合囊蕨的发生和发展;中侏罗世以后逐渐温凉、干燥的气候大大缩减了该属的生存空间,并最终导致其绝灭。
Marattiopsis is a fossil genus of the primitive pachyrhizi in the fern phylum, and is an important component of the Mesozoic plant community. Part of the fossilized specimens containing reproductive organs are often classified as the genus Marattia by virtue of their similar morphology to the existing plants. Although the use of Marattiopsis and Marattia has always been controversial, the former is mostly used for bare-feather specimens, while the real feather specimens are often used as nematodes. However, recent molecular evidence indicates that Marattia is a cotyledon and the original definition has changed. Therefore, only the genus Marattiopsis should be retained and used for fossil specimens. In the Mesozoic, 9 species of Cyclotella genus were identified in the Mesozoic in China. Their temporal and spatial distribution showed that this genus appeared in the Late Triassic and its differentiation peaked, but only distributed in southern China. Early Jurassic However, the number of producing areas increased slightly and spread from South China to North China. The degree of differentiation and origin of the Middle Jurassic declined sharply, with only a small amount of remnant in the northeast. From the Late Jurassic to the entire Cretaceous, it completely disappeared . In this paper, the diversity and temporal-spatial distribution patterns of Cygnalis are closely related to the comprehensive effects of paleoclimate and paleogeography. The hot and humid climatic conditions from Late Triassic to Early Jurassic are favorable for the occurrence and development of Cygnosis. After the Middle Jurassic gradually cool, dry climate greatly reduced the genus’s living space, and eventually lead to its extinction.