The Qinghai-Tibetan Plateau, recognized as the largest and highest plateau on Earth, is often referred to as the “Roof of the World/Third Pole/Water Tower of Asia”. The plateau is characterized by its geological evolution history and abundant rock outcrops, providing a unique perspective for investigating the history of the Earth. The Himalaya Terrane is located at the southernmost part of the Qinghai-Tibetan Plateau. A multitude of studies had suggested that the Himalaya Terrane was located in the peri-Gondwanan region and a warm low latitude zone during the Ordovician. Strata in the Mt. Qomolangma region of southern Xizang yields a significant number of fossils, including brachiopods, gastropods, graptolites and conodonts, resulting in the recognition of the Ordovician in this area. Ordovician cephalopod fossils from southern Xizang have been studied for nearly half a century, while biological composition and relative palaeobiogeography was unclear due to sporadic occurrences.
Recently, the Early Palaeozoic research team from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, and researchers from other affiliations studied Middle to Upper Ordovician cephalopod material from southern Xizang. The results were recently published on Palaeogeography, Palaeoclimatology, Palaeoecology.
Based on a collection of 43 cephalopod specimens from the Jiacun section, 30 species within 16 genera belonging to 10 families and 6 orders have been identified (including two new species: Wutinocerasmultiseptum and Wennanocerasremotum). Genera Lituites, Rhynchorthoceras, Trocholites and Deiroceras are firstly identified in southern Xizang, improving the cephalopod records and deepening the understanding of the cephalopod fauna diversity. Some new cephalopod occurrences suggested the lower part of the Hongshantou Formation is likely of early to middle Katian age. Furthermore, all the cephalopod fossil collections from southern Xizang have been summarized, and the biological diversity and composition research have been conducted. Actinocerid cephalopods were suggested as the dominant group during the Middle Ordovician. Subsequently, in the Late Ordovician, orthocerid and lituitid cephalopods were predominant.
Igraph R package-based network analysis detects the existence of transitional cephalopod communities in the northeastern peri-Gondwana region, which were essential biogeographic bonds facilitating the exchange of cephalopods among various regions during the Middle and Late Ordovician.
This work was supported by the Second Tibetan Plateau Scientific Expedition and Research Program, the National Natural Science Foundation of China and the Chinese Academy of Geological Sciences. This is a contribution to IGCP Project 700 (Palaeozoic Carbonate Build-ups in Southeast Asia) and Project 735 (Rocks and the Rise of Ordovician Life).
Reference: Song, J.Q., Fang, X.*, Li, W.J., Wang, W.H., Burrett, C., Yu, S.Y., Qie, W.K., Zhang, Y.D., 2025. New cephalopod material of Middle to Upper Ordovician from southern Xizang (Tibet), China: Taxonomy, diversity and palaeobiogeography. Palaeogeography, Palaeoclimatology, Palaeoecology, 662, 112744. https://doi.org/10.1016/j.palaeo.2025.112744
Figure 1 Geological and locational map of the Ordovician Jiacun section
Figure 2 New Ordovician cephalopod material from southern Xizang (Tibet), China
Figure 3 Network analyses on cephalopod genera in the northeastern peri-Gondwana region during the Ordovician, and palaeogeographical maps showing the communities
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