Miospores from the Upper Devonian and lowermost Carboniferous strata of the Khoshyeilagh area, northeastern Alborz, Iran

Diverse and well-preserved terrestrial palynomorphs occur in the Padeha, Khoshyeilagh, and Mobarak formations in the Khoshyeilagh area, northeastern Alborz, northern Iran. The spore assemblages consist of 36 species belonging to 24 genera. The vertical distribution of index spores allows the erection within these strata of five local biozones (BT, FF, LE, LN, and VI). The data show that assemblages recorded from the Khoshyeilagh section can be correlated with the VCo, LE, LN, and VI Miospore biozones of Europe, Canada, and USA. Many of the palynomorph species, such as Archaeoperisaccus ovalis, Ancyrospora ampulla, Diducites mucronatus, D. versabilis, Grandispora cornuta, G. echinata, Indotriradites explanatus, Retispora lepidophyta, Retusotriletes incohatus, R. phillipsii, Rugospora flexuosa, Teichertospora torquata, Tumulispora malevkensis, Vallatisporites pusillites, Verrucosisporites bulliferus, and Verrucosisporites nitidus, are closely comparable with coeval assemblages recorded from Belgium, Portugal, Canada, North Africa, South America, and North America. This indicates the close relationship of the Iranian Platform to other parts of the northern Gondwana and southern Laurentian domain during this time interval. Moreover, parent plants of the Late Devonian miospores in the Khoshyeilagh area generally belong to herbaceous Class Rhyniopsida (orders: Rhyniales, Trimerophytales), Zosterophyllopsida, and various classes such as, Lycopsida (herbaceous order: Isoetales, Selaginellales, Protolepidodendrales), Progymnospermopsida (Order Archaeopteridales and Aneuropthytales), and Filicopsida. The presence of marine shelly macrofauna (brachiopods and corals) suggest a nearshore depositional environment comprising rivers, fluvial deltas, tidal flats, and lagoons for the Upper Devonian and lowermost Carboniferous deposits studied herein.

伊朗北部厄尔布尔士山脉东北部霍谢伊拉格地区的帕德哈组（Padeha）、霍谢伊拉格组（Khoshyeilagh）与穆巴拉克组（Mobarak）地层中，产出多样且保存完好的陆生孢粉型化石（terrestrial palynomorphs）。该孢子组合包含隶属于24个属的36个物种。指示孢子的垂向分布特征，使得可在上述地层中建立5个地方性生物带（BT、FF、LE、LN及VI）。研究数据表明，霍谢伊拉格剖面的孢粉组合可与欧洲、加拿大及美国的VCo、LE、LN和VI陆生孢子（miospore）生物带进行对比。诸多孢粉型物种，如Archaeoperisaccus ovalis、Ancyrospora ampulla、Diducites mucronatus、D. versabilis、Grandispora cornuta、G. echinata、Indotriradites explanatus、Retispora lepidophyta、Retusotriletes incohatus、R. phillipsii、Rugospora flexuosa、Teichertospora torquata、Tumulispora malevkensis、Vallatisporites pusillites、Verrucosisporites bulliferus及Verrucosisporites nitidus，均与比利时、葡萄牙、加拿大、北非、南美及北美产出的同期孢粉组合极为相似。这反映出该地质时段内，伊朗板块与冈瓦纳大陆北部其他区域以及劳伦大陆南部域存在密切的亲缘联系。此外，霍谢伊拉格地区晚泥盆世陆生孢子的母体植物，大致可归入草本莱尼蕨纲（Rhyniopsida，包含莱尼蕨目Rhyniales、三枝蕨目Trimerophytales）、工蕨纲（Zosterophyllopsida），以及石松纲（Lycopsida，涵盖草本的水韭目Isoetales、卷柏目Selaginellales、原始鳞木目Protolepidodendrales）、前裸子植物纲（Progymnospermopsida，包含古蕨目Archaeopteridales与无脉蕨目Aneuropthytales）以及真蕨纲（Filicopsida）。海生贝壳类大型动物群（腕足类与珊瑚类）的产出，表明本次研究的上泥盆统及下石炭统最底部沉积的沉积环境为近岸环境，包括河流、河流三角洲、潮坪及泻湖。