Cunninghamia praelanceolata sp. nov. with associated epiphyllous fungi from the upper Miocene of eastern Zhejiang, S.E China and their palaeoecological implications

Abstract

Cunninghamia praelanceolata sp. nov. (Cupressaceae) is described from the upper Miocene Shengxian Formation of eastern Zhejiang, Southeast China. The fossil leaves are characterised by a lanceolate shape, serrulate margins, two abaxial stomatal bands with undulate anticlinal walls and mostly parallel or obliquely oriented stomata. They closely resemble the leaves of the extant genus Cunninghamia, particularly C. lanceolata, more than other taxodiaceous genera. The new species is distinct from other fossil Cunninghamia species and Cunninghamia-like plants in leaf morphology and cuticular features. The fungi stromata discovered on the adaxial epidermis of C. praelanceolata are identified as Callimothallus pertusus Dilcher (Microthyriaceae). The lifestyle of epiphyllous fungi and the well-preserved fossil leaves associated with mature fungal stromata may suggest a parasitic interaction. The occurrence of the probably evergreen C. praelanceolata suggests a warm and humid climate in eastern Zhejiang during the late Miocene, which is also supported by the presence of the epiphyllous fungus of Callimothallus pertusus and previously published fossil plants.