This study describes Tubuloreticulaspongia sinensis n. gen. n. sp., a new protospongiid sponge from the Hirnantian (Upper Ordovician) to Rhuddanian (Lower Silurian) of South China. The genus exhibits a tubular body, orthogonal skeletal mesh, and pentactine spicules with elongated vertical rays and short latitudinal rays, distinguishing it from related taxa. Its inward-oriented unpaired rays and delicate structure suggest adaptation to calm, nutrient-poor offshore environments. The discovery extends our knowledge of reticulosan evolution following the Late Ordovician Mass Extinction, and adds a further example of Cambrian-like skeletal traits persisting into the Ordovician-Silurian transition. These findings complement the reticulosan sponge evolution, ecological resilience, an d the role of regional settings in post-extinction recovery. The species is also the first sponge species identified from two distinct faunas in the Ordovician-Silurian transition of South China. (c) 2026 Nanjing Institute of Geology and Palaeontology. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.