Occurrence of Brachyoxylon Hollick et Jeffrey from the Lower Cretaceous of Zhejiang Province, southeastern China

Abstract

The Lower Cretaceous Guantou Formation is known as an important horizon for the Cretaceous petrified woods in southern China. Though abundant Cretaceous wood remains have been found in this formation, only one species has been recognized. A new coniferous wood, Brachyoxylon zhejiangense sp. nov. is described from the Lower Cretaceous Guantou Formation in Xinchang of Zhejiang Province, southeastern China. Anatomically, the new species is characterized by obscure annual rings, mixed type of radial pitting, araucarioid cross-field pits and uniseriate xylem rays. The finding of Brachyoxylon zhejiangense sp. nov. represents the first well-defined record of Brachyoxylon in southeastern China, and enriches the diversity of the Early Cretaceous petrified wood in southern China. Additionally, the new finding sheds new light on further understanding the floral composition, especially the forest vegetation type of the southern phytoprovince in the late Early Cretaceous. Diverse compressed leaf fossils of Cheirolepidiaceae have been described from the Guantou Formation in the fossil locality of the present petrified wood. The co-occurrence of Brachyoxylon zhejiangense sp. nov. and those cheirolepidiaceous leaf fossils provide additional evidences to support that Brachyoxylon may be systematically related to the Cheirolepidiaceae.