Mingli Wan

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.

Searching for land refugia becomes imperative for human survival during the hypothetical sixth mass extinction. Studying past comparable crises can offer insights, but there is no fossil evidence of diverse megafloral ecosystems surviving the largest Phanerozoic biodiversity crisis. Here, we investigated palynomorphs, plant, and tetrapod fossils from the Permian-Triassic South Taodonggou Section in Xinjiang, China. Our fossil records, calibrated by a high-resolution age model, reveal the presence of vibrant regional gymnospermous forests and fern fields, while marine organisms experienced mass extinction. This refugial vegetation was crucial for nourishing the substantial influx of surviving animals, thereby establishing a diverse terrestrial ecosystem approximately 75,000 years after the mass extinction. Our findings contradict the widely held belief that restoring terrestrial ecosystem functional diversity to pre-extinction levels would take millions of years. Our research indicates that moderate hydrological fluctuations throughout the crisis sustained this refugium, likely making it one of the sources for the rapid radiation of terrestrial life in the early Mesozoic.

The late Palaeozoic is the key period for understanding the origin and early evolution of insects, but Palaeozoic insects from China are poorly explored. Up to now, a total of 53 Carboniferous species, 27 Permian species and 1 Carboniferous–Permian species (12 orders or 2 superorders) have been described. Recently, with the development of biostratigraphy and isotope chronology, new insights into the stratigraphy of China and its timescale have been greatly improved. In this study, we discuss the ages of published Palaeozoic insects from China and summarize 23 Carboniferous species, 57 Permian species and 2 Carboniferous–Permian species.

Plants and arthropods interact with each other and constitute an important part of the modern terrestrial ecosystem (Schoonhoven et al., 2005). Historically, fossil records of plant-arthropod interactions have been well documented in Paleozoic terrestrial ecosystems, which were evidenced by large coprolites containing various plant fragments (e.g., Salter et al., 2012), small larvae and coprolites remained in plant organs (e.g., Feng et al., 2017), and diverse functional feeding groups discovered on plant stems, rachises, roots, leaves and fertile organs (e.g., Liu et al., 2020).

A silicified trunk, Zhuotingoxylon liaoi Wan, Yang, Wang, Liu et Wang gen. et sp. nov., is described from the uppermost part of Guodikeng Formation in South Taodonggou section, Turpan–Hami Basin, Xinjiang Uygur Autonomous Region, northwestern China. It is characterized by a solid pith, endarch primary xylem and pycnoxylic wood. The pith is composed of parenchyma and sclereids. Radial walls of primary xylem tracheids have spiral and scalariform thickenings. Secondary xylem consists of thick‐walled tracheids and parenchymatous rays. Uniseriate rounded pits with oval apertures are distributed on radial tracheidal walls separately. Cell walls of rays are homogeneous and smooth. Rays are 1–10 cells high in tangential section. Cross‐field pits are cupressoid. There are 1–4 bordered pits with slit‐like to oval apertures in each cross‐field. Based on the anatomical features of the pith and xylems, it is proposed that the new stem has a coniferous affinity. The new fossil stem adds to the knowledge of vascular plant diversity close to the Permian–Triassic boundary.