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The protolepidodendralean lycopsid Leclercqia represents one of the best studied Devonian plants, with a worldwide distribution, but is not known from the palaeocontinents that constitute the present northeastern China. Two species of the genus, Leclercqia cf. L. complexa and Leclercqia sp., are described for the first time from the Hanuo Obo Formation of Dong Ujimqin Qi, Inner Mongolia, northeastern China, an area poorly documented by record of early vascular plants. The first species is characterized by three‐dimensional, five‐tipped leaves, which show a long, downwardly recurved, central segment and two pairs of short, lateral segments, while the latter species bears seven‐tipped leaves and more robust axes. Our discovery confirms that the Hanuo Obo Formation is a distinctive lithological unit in Inner Mongolia, and suggests a Middle to Late Devonian (but no later than Frasnian) age for this formation based on the global spatio‐temporal occurrence of Leclercqia. The present finding indicates the spread of protolepidodendraleans to the Xing'an Block, or a part of the Mongolian Block, representing the northernmost distribution of this group during the Devonian. [ABSTRACT FROM AUTHOR]

Abstract The Gzhelian (Late Pennsylvanian) reefs of the Amushan Formation in eastern Inner Mongolia, North China, were formed by filamentous microbes and phylloid algae. Loosely accumulated prostrate phylloid algae provided substrates for growth of filamentous microbes to construct a rigid reef framework. Filamentous microbes grew parallel to the surfaces of phylloid algae, forming micritic encrustations. Subsequent developed stage of the filamentous microbes, growing perpendicularly to the phylloid algae surfaces, produced the peloid-A aggregations (concentrated areas of peloids of A type). The remaining spaces in the phylloid algal–microbial frameworks were filled by microbes that grew perpendicularly to the phylloid algae surfaces, generating peloid-B aggregations (concentrated areas of peloids of B type). Microbial sediment with various proportions of phylloid algae is a significant character of the Gzhelian buildups in the subtropical North China. North China buildups have similar reef-building organisms to the typical Tethyan buildups, but have a different construction model. As such, the subtropical North China buildups are considered as a sub-type of the tropical Tethyan buildups. [ABSTRACT FROM AUTHOR]

The Sakmarian–Kungurian (Early Permian) carbonate mounds of the Amushan Formation of the Deyanqimiao section in eastern Inner Mongolia, North China comprise phylloid algae-echinoderm mound, fusulinid-echinoderm mound and echinoderm mound. They were constructed by repeating the following steps in the mid-ramp and outer ramp environments: 1) skeletal grains accumulated in situ, or after short-distance transportation; 2) tubiform microbes eroded skeletal grains, induced the formation of CaCO 3 crystallites near the cell surface, and trapped and bound suspended lime mud from ambient water; 3) some positive topographies slightly higher than adjacent sediments were formed. Data from North China, as well as the tropical Tethyan domain and the subtropical Pangean domain show a three-phase development pattern of Early Permian carbonate buildups. The first phase (Asselian-Sakmarian) is marked by carbonate buildups rich in organisms, such as phylloid algae, Palaeoaplysina , Shamovella , sponges and bryozoans. The second phase (Artinskian) is represented by the disappearance of phylloid algae and Palaeoaplysina from carbonate buildups resulted from the paleoclimatic change from an icehouse to a greenhouse. The third phase (Kungurian) is characterized by the sharp contrast between drastic decline of carbonate buildups in the subtropical Pangean domain and their successful development in North China and the tropical Tethyan domain. [ABSTRACT FROM AUTHOR]

The Silurian and Devonian plant fossil record is the basis for our understanding of the early evolution of land plants, yet our appreciation of early global phytogeographic evolution has been constrained by the focus of most studies on deposits from Europe, North America, and, more recently, South China. Devonian plants have been recorded rarely from northeastern China, and among previous records, few plants have been illustrated and formally described. In this article, megafossil plants representing a Late Devonian-aged (probably Famennian) flora are described from a locality at northern Sonid Zuoqi, Inner Mongolia, NE China. The flora includes Melvillipteris sonidia new species, Archaeopteris sp., and fragments of some other plants. The new plant shows main axes and two orders of lateral branches. The first-order branches of this plant show a typical zigzag appearance and are borne in pairs on main axes. Second-order branches are straight or slightly flexed, and are borne helically or alternately on first-order branches. Sterile ultimate appendages and fertile structures of M. sonidia n. sp. are borne alternately on second-order branches. An associated palynological assemblage, as well as U-Pb ages of detrital zircon grains from adjacent horizons, are also reported, indicating a Late Devonian age in accord with the megafossil plants. The present study contributes to our appreciation of the Devonian floristic diversity of the Xing'an Block, and, through our review of the record of early vascular plants from NE China, more broadly to the understanding of the mid-latitude vegetation of the Northern Hemisphere during the Late Devonian. [ABSTRACT FROM AUTHOR]