A petrified wood Brachyoxylon from the Lower Cretaceous of Bangoin, Tibet (Xizang), Southwest China

Abstract

A new species of conifer wood, Brachyoxylon lalongense sp. nov., was discovered from the Lower Cretaceous Duoni Formation of Bangoin County in the northern part of the Lhasa Block, Southwest China. The anatomical structure of the secondary xylem is characterized by the absence of growth rings, mixed type of radial tracheary pitting, araucarioid cross-field pits, uniseriate xylem rays, and the absence of resin canals. The absence of growth rings in the secondary wood indicates that this conifer was evergreen and the area was dominated by a hot climate during the Early Cretaceous. This conclusion is coincident with the coeval palaeobotanical and palynological evidences discovered in Tibet.