Chunlin Sun

A Study of Ginkgo Leaves from the Middle Jurassic of Inner Mongolia, China1

During the Mesozoic era, Ginkgo leaves are diverse and widespread, especially in the Northern Hemisphere. Here we present three Ginkgo leaf types collected from the Middle Jurassic Zhaogou Formation of Shiguai coal‐bearing basin in Inner Mongolia, China. These are described for the first time on the basis of their leaf morphology and well‐preserved cuticular characters. One new species, Ginkgo shiguaiensis, is described, and Ginkgo longifolius is recognized, while a third leaf type is designated as Ginkgo sp. The occurrence of these leaf types in the Middle Jurassic of Inner Mongolia significantly extends the stratigraphic and geographic distribution of Ginkgo in China. The associated plants, cuticular characters of the Ginkgo leaves, and the sedimentology of the plant‐bearing strata suggest that these plants grew in a warm‐temperate and moist climate.

Czekanowskia from the Jurassic of Inner Mongolia, China

The genus Czekanowskia is an important member of the Mesozoic flora and is widespread in the Northern Hemisphere. In China, it is found mostly in Late Triassic and Early and Middle Jurassic sediments of North China. With the exception of a few specimens, all the reports of this genus from China have been based on gross leaf morphology. Abundant Czekanowskia leaves, preserved as compression fossils, were collected from the Middle Jurassic, Zhaogou Formation of Inner Mongolia, China. In this article, two subgenera of Czekanowskia, Harrisella and Vachrameevia, are recognized from Inner Mongolia, China, on the basis of leaf morphology and epidermal characters. Two new species, Czekanowskia chinensis sp. nov. (subg. Harrisella) and Czekanowskia shiguaiensis sp. nov. (subg. Vachrameevia), are described. The occurrence of these species in the Middle Jurassic of Inner Mongolia significantly extends the stratigraphic and geographic distribution of Czekanowskia in the Northern Hemisphere. Analysis of the epidermal characters of material presented here along with consideration of other associated plants of the flora and sedimentology of the plant‐bearing strata suggests that the two species described in this report grew in an area with a warm and humid climate in a warm temperate zone. Biostratigraphic correlation of the plant‐bearing strata indicates that the specimens described here are Middle Jurassic in age.

Nilssoniopteris binggouensis sp. nov. (Bennettitales) from the Lower Cretaceous of Northeast China

Premise of research. A new species, Nilssoniopteris binggouensis (Bennettitales), is recognized from the Lower Cretaceous Binggou Formation from western Liaoning Province, northeast China. This is the first time that fossil plants are reported from the Early Cretaceous Binggou Formation from Liaoning Province. The new species is one of the youngest-known Bennettitales from China. Methodology. Fossil specimens were examined using SEM and LM and were compared with other published taxa. Pivotal results. Based on leaf morphology and epidermal characters, we describe a new species, N. binggouensis. The leaf is petiolate with entire margin and fine, parallel lateral veins. The leaf lamina is hypostomatic. The anticlinal walls of epidermal cells are strongly and tightly folded. The stomatal apparatus is brachyparacytic (=syndetocheilic). Conclusions. The occurrence of the new species in the late Early Cretaceous of western Liaoning Province significantly extends the stratigraphic and geographic distribution of the genus Nilssoniopteris in the Northern Hemisphere. It represents one of the easternmost occurrences of this predominantly Eurasian genus. This report increases our knowledge of this Early Cretaceous fossil site and improves our understanding of the diversity of the Bennettitales.

The First Discovery of the Easternmost Jehol Biota from Southeastern Jilin, China

The Jehol Biota, a world-famous Early Cretaceous fossil Lagerstätte characterized by the traditional Eosestheria-Ephemeropsis-Lycoptera (EEL) assemblage, has a wide distribution over most parts of northern China, the coastal area of southeastern China, southeastern Mongolia, Transbaikalian area of Russia, Korea and Japan (Shao et al., 2017). The Baishan Basin, situated in southeastern Jilin is one of the easternmost Jehol Biota localities in China. Until now, the fossils here belonging to Jehol Biota have not yet been reported except for few fossils listed in geological survey reports. The fossil collections here are noteworthy in that they are the first fossil record documented from the Early Cretaceous Yingzuilazi Formation of the Baishan Basin, southeastern Jilin and the easternmost locality of Jehol Biota, China. This finding is important to explore the distribution, evolution and biodiversity of the Jehol Biota and even the Late Mesozoic terrestrial ecosystem, as well as for the division and correlation of the Late Mesozoic terrestrial strata.