Middle Jurassic plant fossils
“This study presents the first report on Middle Jurassic plant fossils from the Khamarkhoovor Formation, Dovtsog Khudag area, East Gobi Basin, Mongolia. 20 species of fossil plants from 11 genera have been identified, including liverworts, horsetails, ferns, cycadophytes, ginkgophytes, czekanowskialeans and conifers. Based on sedimentological analysis and plant assemblages, we interpret the depositional environment as alluvial plain and swamp. Alluvial plain deposits are characterised by the presence of ginkgophytes, cycads (Nilssonia) and conifers (Pityophyllum). The swamp environment is characterised by Czekanowskiales (Czekanowskia, Phoenicopsis), horsetails (Equisetites) and ferns (Coniopteris, Cladophlebis). The most significant species for phytostratigraphy are Coniopteris snigirevskiae, Cladophlebis haiburnensis, Cl. akulovii (ferns), Czekanowskia (Subg. Vachrameevia) teslenkoi, and Phoenicopsis (Subg. Phoenicopsis) angustifolia. The fossil plant remains, combined with published data on the phytostratigraphy of Jurassic sedimentary basins in Mongolia, as well as adjacent regions of China and Siberia, suggest that the studied deposits of the Khamarkhoovor Formation belong to the Middle Jurassic, most likely the Aalenian–Bajocian stages. The studied flora corresponds to the Siberian Floristic Province, which comprises warm-temperate elements and indicates seasonal climatic fluctuations.” See the publication