Early Jurassic Flora and Stratigraphy from Shansonggang of Southern Jilin,China

More than 35 species belonging to 22 genera of fossil plants are recognized by the authors from the Shan-songgang flora in the Shansonggang Basin of Jilin, China. Among them, the coexistence of Coniopteris and Cycadocarpi-dium demonstrates that the present flora possesses the characters of the early assemblage of Early Jurassic floras in Eura-sia. Therefore, the age of the Shansonggang flora is considered the Early Jurassic.This study would be beneficial for bet-ter understanding the paleoecological and paleoclimatic characteristics of the Shansonggang Basin. Based mainly on the characters of the flora, the authors suggest that the Lower Jurassic coal-bearing strata, the Shansongang Formation, should namely be renewed.

Flabellariopteris, a new aquatic fern leaf from the Late Triassic of western Liaoning, China

An aquatic fern leaf,Flabellariopteris mii Sun gen.et sp.nov.from the Late Triassic of Western Liaoning,China,is described and proposed as the type species of the new morphortaxon of the Marsileaceae.The fossil leaves are preserved as impression.No fertile and rhizomatic materials are found.The leaves attached at a common point on the top of the petiole are composed of two leaflets joined basally in an opposite arrangement.The petiole is slender.The leaflet is fan-shaped or semi-circular,and commonly divided into four wedge-shaped lobes.Terminal margin of lobes is usually incised,incisions shallow or deep,with bluntly rounded or notched apex.The veins are conspicuously dichotomous,but anastomoses and marginal vein are absent.The unique morphological features,including twoparted thin leaflets,size,shape,veins and slender petiole,indicate that the present specimen represents an aquatic fern,which is the oldest fossil record and the first megafossil evidence assignable to Marsileaceae from the Triassic floras.

An introductory report on the biodiversity of Middle Jurassic Phoenicopsis(Czekanowskiales) from the Ordos Basin, China

Although the genus Phoenicopsis is the most common member of Czekanowskiales and is considered an indicative representative of the Middle Jurassic Coniopteris–Phoenicopsis assemblage in northern China, little was known about its taxonomy and biodiversity based upon the leaf cuticular structure. In this paper, three subgenera of the genus Phoenicopsis from the Middle Jurassic, Yan'an Formation of the Ordos Basin, China, Phoenicopsis(subg. Phoenicopsis)(Heer) Samylina, P.(subg. Windwardia)(Florin) Samylina and P.(subg. Culgoweria)(Florin) Samylina are identified based upon the leaf epidermal features for the first time. This discovery demonstrates that Phoenicopsis was quite diverse during the Middle Jurassic in northern China. Its biodiversity is significant for further understanding Middle Jurassic paleophytogeography and paleoclimatology of northern China. The current findings show that the three Phoenicopsis subgenera coexisted and flourished in the mixed zone(ecotone) between the Indo-Sinian Floristic Region and the Siberian Floristic Region as seasonal deciduous plants(trees or shrubs) during the Middle Jurassic. They were important elements in the Middle Jurassic deciduous gymnospermous forest community in warm temperate regions with seasonal temperature and precipitation variations. They are interpreted as growing on the hillsides and sloping fields along meandering streams, lakes and swamps in a vast sedimentary basin in a wet and warm environment.