First fossil record of Nothotsuga (Pinaceae) in China: implications for palaeobiogeography and palaeoecology

Abstract

ABSTRACT Nothotsuga is a monotypic genus of Pinaceae endemic to southern China today. Molecular data indicate that Nothotsuga split from Tsuga during the Palaeogene with the earliest fossils from the upper Eocene of North Europe. However, Nothotsuga fossil has not been reported from China. Here, we describe several well-preserved seed cones from the upper Miocene of Tiantai County, Zhejiang Province, China. The fossil cones are characterised by ovate to elliptic shapes, rhombic to suborbicular and auriculate scales, and exserted subspathulate bracts with dentate margin and acute or acuminate apical cusp. These cones are ascribed to a new species Nothotsuga sinogaia sp. nov. based on detailed comparisons with all extant genera of Pinaceae. The present discovery indicate that Nothotsuga had a more northern distribution during the late Miocene and the increased annual range of monthly-mean temperature might have restricted its modern distribution to several scattered and fragmental areas in southern China.