Fu-Jun Ma

Paliurus Fruits from the Oligocene of South China and Their Phytogeographic Implications

Paliurus favonii Unger is recognized and described based on fruits from the Oligocene Ningming flora of Guangxi, South China. Characteristics of the present specimens include circular winged fruits that are 10.0–11.5 mm in diameter with a central endocarp at 3.0 to 4.0 mm in diameter. The specimens fall into the morphological range of the fossil species P. favonii, which has been observed in other Cenozoic sites in the Northern Hemisphere. The present discovery represents the lowest latitude distribution of P. favonii in the world, and we are presenting the first P. favonii fossil described with detailed cuticular characteristics from China. Further, this finding demonstrates that the genus existed in the Oligocene Ningming region, South China, and provides new information for understanding the fossil history. The dispersal mode for winged fossils demonstrates that wind dispersal is well-represented in the Oligocene Ningming flora.

A new species of Meliolinites associated with Buxus leaves from the Oligocene of Guangxi, southern China

A new species of Meliolinites (fossil Meliolaceae), M. buxi sp. nov., is reported from the Oligocene Ningming Formation of Guangxi, South China. The fungus has hyphopodia characteristics of extant Meliolaceae, such as thick-walled, branching hyphae with appressoria and phialides. However, these fossils entirely lack mycelial or perithecial setae and have only a few phialides, thereby distinguishing the new species from most known species. The fungus was discovered on the adaxial and abaxial cuticles of several fossilized Buxus leaves. Thickening and twisting of cell walls in the Buxus leaf cuticle, along with the parasitic feeding strategy of the extant Meliolaceae, suggest that a parasitic interaction between Buxus and M. buxi seems feasible. The distribution of modern Meliolaceae suggests that they live in warm, humid subtropical-tropical climates. It is possible that the presence of M. buxi indicates a similar climatic condition. The co-occurrence of large-leaf Buxus and floristic comparisons of the Ningming assemblage also corroborate this conclusion.

A new species of Zelkova (Ulmaceae, Ulmoideae) with leaves and fruits from the Oligocene of South China and its biogeographical implications

A new fossil species of Zelkova is described from the Oligocene Ningming Formation of Guangxi, South China. Zelkova ningmingensis sp. nov. is characterized by leaves with craspedodromous venation pattern and drupaceous fruit type. The new species possesses elliptical to ovate leaves, bearing 7–12 pairs of secondary and simple toothed margin, as well as epidermal cells with straight or rounded anticlinal walls. The species is compared with extant and other fossil species hitherto reported of the genus. It is most similar to the living Zelkova schneideriana in the leaf gross morphology and epidermal characters, which may be suggested to be the ancestral type of Zelkova schneideriana. The discovery of Zelkova ningmingensis sp. nov. in Guangxi indicates that Zelkova has already existed in southern China as early as the Oligocene. In combination with Zelkova material from the Oligocene of Europe, it can be inferred that Eurasian Zelkova had begun to diversify by at least the Oligocene. Because China is the biodiversity centre of modern Zelkova, the fossil herein provides new insights into Zelkova biogeography.

New costapalmate palm leaves from the Oligocene Ningming Formation of Guangxi, China, and their biogeographic and palaeoclimatic implications

Abstract New palm leaves from the Oligocene Ningming Formation are placed into the morphogenus Sabalites because of their costapalmate leaf shape. Four taxa are described on the basis of leaf compressions with cuticular structure. S. guanxiensis sp. nov. is characterised by hypostomatic leaf blades with a stout costa and a symmetrical base. Sabalites cf. asymmetricus has amphistomatic leaf blades with a long, delicate costa and an asymmetrical base. Sabalites sp. 1 has amphistomatic leaf blades with a long, massive costa and wide segments. Sabalites sp. 2 is characterized by hypostomatic leaf blades with a prominent costa and an asymmetrical base. The four new palm taxa expand our understanding of the floristic elements and features of the Oligocene Ningming flora. Together with the other three palm taxa that were previously reported from the Ningming Formation, our material indicates that the Oligocene Ningming flora had a rich diversity of costapalmate palms. The relatively high species diversity of palms and other plants corroborate that the Oligocene Ningming flora represents a warm and humid climate.

Two new Castanopsis (Fagaceae) species based on cupule and foliage from the upper Miocene of eastern Zhejiang, China

Two new species, Castanopsis praefissa R.Y. Li et B.N. Sun sp. nov. and Castanopsis praeouonbiensis R.Y. Li et B.N. Sun sp. nov., are described from fossil specimens collected from the upper Miocene Shengxian Formation, Zhejiang Province, Southeast China. The fossil leaves are obovate to elliptical with serration mostly confined to the upper 1/3 of the lamina, pinnate venation, straight anticlinal walls and cyclocytic stomata. The fossil cupule is globose with fasciculate and branched spines, and a broadly ovate nut scar. The fossil leaves and cupule have been compared with those extant and other fossil species hitherto described in this genus. Castanopsis praefissa shows the closest affinity to C. fissa, and C. praeouonbiensis closely resembles C. ouonbiensis. Castanopsis fissa has toothed leaves and scaly cupules, whereas C. ouonbiensis has untoothed leaves and spiny cupules. Furthermore, they were not collected from the same site. So it is reasonable to assign them to two different species, rather than to one. Castanopsis praeouonbiensis and C. praefissa became extinct in this area because of the cooling climate from the late Miocene to the present day in Zhejiang Province.