Abstract Orthoptera constitutes an important ecological component of the global fauna, but the order's Early Jurassic record is limited in China and its evolution is poorly understood after the end-Triassic mass extinction. Several orthopterans are described herein from the Lower Jurassic Badaowan and Sangonghe formations of the southern Junggar Basin, Xinjiang, NW China. From the Badaowan Formation, a new species, Parahagla cheni sp. nov., is established and assigned to Chifengiinae (Hagloidea: Prophalangopsidae), which represents the oldest record of this subfamily. From the Sangonghe Formation, a forewing fragment is attributed to Sinagryllus xinjiangensis Wang et al. , 2019 (Grylloidea: Baissogryllidae); another forewing fragment and a metathoracic leg without attribution are also described. The discovery of these fossils increases the biodiversity of Orthoptera in the Early Jurassic, and further indicates that orthopterans probably flourished in the Junggar area during the Early Jurassic. An analysis of orthopteran biodiversity at generic and species levels reveals an extinction in Orthoptera in the Late Triassic, especially for the superfamilies Hagloidea and Oedischioidea, which suffered a substantial extinction. This extinction occurred in the Late Triassic, earlier than the mass extinction of marine animals at the end of the Triassic.

Abstract The Pingyi Basin is a late Mesozoic to Cenozoic fault basin in East China, containing a good record of Cretaceous to Paleogene non-marine carbonate and gypsum deposits. Abundant microfossils including gastropods, ostracods, charophytes and palynomorphs have been reported from this basin. A taxonomic study of ostracods from the Gejiazhuang section in the Pingyi Basin reveals a total of 17 species assigned to 11 genera. A further ostracod biostratigraphic correlation suggests the K/Pg boundary lies within Member 1 of the Bianqiao Formation in the Gejiazhuang section, which is supported by charophyte biostratigraphy.

Abstract Oceanic Anoxic Event (OAE) 1b is well documented in western Tethys; however, records in Eurasia are still lacking. Here, we carried out high-resolution organic carbon isotope (δ 13 C org ), total organic carbon (TOC) content and mercury (Hg) concentration analysis of the lacustrine sediments from the Xiagou and Zhonggou formations in the Hanxiagou section of the Jiuquan Basin, NW China. The lacustrine δ 13 C org curve presents three stages of negative excursions above the basalt layer dated at 112.4 ± 0.3 Ma in the lowermost Zhonggou Formation. The three negative δ 13 C org excursions correspond well with the three sub-events (Kilian, Paquier and Leenhardt) of the OAE 1b in the Poggio le Guaine (central Italy), Vocontian Basin (SE France) and St Rosa Canyon (NE Mexico) sections, supporting the record of the terrestrial OAE 1b in the Jiuquan Basin. Five mercury enrichment intervals in Hg/TOC ratios were recognized, indicating that the pulsed volcanism from the Southern Kerguelen Plateau likely triggered OAE 1b. However, the decoupling between negative isotopic excursion shifts and mercury enrichments, signifying another carbon reservoir (with no link to mercury), probably contributed to the global carbon cycle perturbation during the OAE 1b period. Our results provide direct evidence to link OAE 1b and the terrestrial ecosystem in Eurasia.