Ningxiaites specialis, a new woody gymnosperm from the uppermost Permian of China

Abstract

An exquisitely well-preserved woody stem from northern China provides additional evidence for the biodiversity of latest Permian of the Cathaysian flora. The specimen of Ningxiaites specialis gen. nov. et sp. nov. was collected from the Sunjiagou Formation in the Shitanjing coalfield, Ningxia Hui Autonomous Region. The permineralised plant is featured by a eustelic vascular system, thick pycnoxylic woody cylinder, and prominent helically arranged clusters of leaf traces. The circular parenchymatous pith is surrounded by more than 30 endarch primary xylem strands and numerous distinctive leaf traces. Leaf traces initiate from the pith margin singly, bifurcate immediately or remain as a single bundle when crossing the wood cylinder. The wood is especially characterised by the development of inflated cells and pitted tangential (terminal/end) wall of ray cells. The new plant is tentatively assigned to the conifers although it shows few similarities with ginkgophytes, which might indicate the early conifer and ginkgophyte woods could be very similar to each other. Spheroidal and oval coprolites preserved in its pith and adjacent xylem is interpreted as having an oribatid mite origin.