Charcoalified Fossil Coniferous Woods From the Late Triassic Alluvial Fan Deposits of Western Junggar Basin, China, and Their Palaeoecological Implications

ABSTRACT Three types of charcoalified coniferous wood are described from the Upper Triassic Shendigou section, western Junggar Basin, Xinjiang Uygur Autonomous Region, northwestern China. They are pycnoxylic, characterised by the dominantly uniseriate radial tracheidal pitting, and parenchymatous and uniseriate rays. Based on anatomical features, these charcoalified woods are comparable with Phyllocladoxylon Gothan, Agathoxylon Hartig, and Taxodioxylon Hartig respectively. The fossil charcoals demonstrate that conifers were integral components of the early Late Triassic terrestrial ecosystem in the Junggar Basin. Considering these fossil charcoal fragments that were collected from the braided channel facies of fan delta plain deposits and the previously reported Protophyllocladoxylon ‐like charcoal from the same interval, it is hypothesised that forests with at least four types of conifers had thrived in upland areas during the Late Triassic in NE Pangaea. Distinct growth rings in the charcoals and previously recorded seed ferns with thick cuticles and deep‐sunken stomatal pores indicate that the early Late Triassic upland forest had been subjected to seasonal climatic variations and wildfire events.