First Records of a Typical East Asian Mesozoic Fossil Wood - Shimakuroxylon in China

Fossil wood is one of the most significant elements for terrestrial vegetation compositions and continental palaeoenvironment reconstruction in deep time. Although paleoxylology have advanced markedly over the past two decades, Jurassic wood record from the Qinghai-Xizang Plateau and Cretaceous wood record from the Zhejiang of south China remain sparse, and detailed anatomical studies are lacking. Here we describe two well-preserved fossil wood specimens，which are from the Middle Jurassic Xiali Formation in Shuanghu County, Qiangtang terrane, Xizang (Tibet), China and the Early Cretaceous Laocun Formation in Longyou County，Zhejiang province. These fossils exhibit the typical Shimakuroxylon Philippe, Boura, Oh et Pons anatomy: shimakurean radial tracheid pitting and araucarioid cross-field pitting, thereby expanding the known diversity of Middle Jurassic fossil wood in Qinghai-Xizang Plateau and Early Cretaceous fossil wood in southern China，refining the floral composition of the Xiali Formation and Laocun Formation, and providing new paleobiogeographic evidence for understanding the distribution of Shimakuroxylon and floristic connections across eastern Asia during the Mesozoic.