A revision of sponges from the Faringdon Sponge Gravel Member and Atherfield Clay Formation, Lower Greensand Group of England

Abstract

Sponges of the Lower Greensand Group (LGS) are well preserved and occur in sediments of a sandy matrix. Abundant in the Faringdon Sponge Gravel Member (FSG), these sponges, mostly Calcareans, are found in Oxfordshire, with notable preservation at Little Coxwell quarries. This study provides descriptions of common species following the updated Porifera classification and recent sponge taxonomy research, illustrated with specimens from the Natural History Museum, London (NHM), British Geological Survey (BGS), and Natural History Museum Basel (NMB) collections. The following taxa are recorded and described: 1) Calcareans: Barroisia anastomosans (Parkinson, 1822), Barroisia clavata (Keeping, 1883), Barroisia irregularis (Hinde, 1884), Dehukia crassa (de Fromentel, 1861), [Elasmoierea] faringdonensis (Mantell, 1854), [Elasmoierea] mantelli (Hinde, 1884), Peronidella gillieroni (de Loriol, 1869), Peronidella prolifera (Hinde, 1884), Peronidella ramosa (Roemer, 1839), Oculospongia dilatate (Roemer, 1864), Tremospongia pulvinaria (Goldfuss, 1826), Raphidonema contortum (Hinde, 1884), Raphidonema porcatum (Sharpe, 1854), Raphidonema farringdonensis (Sharpe, 1854), Raphidonema macropora (Sharpe, 1854), Raphidonema pustulatum (Hinde, 1884), Endostoma foraminosa (Goldfuss, 1826); and 2) Hexactinellids: Lonsda contortuplicata (Lonsdale, 1849). Key findings include the identification of Tethyan biogeographic affinities and ecological adaptations that highlight the role of these sponges in early reef-like systems. By refining species descriptions and linking them to broader Cretaceous ecosystems, this work enhances understanding of sponge biodiversity, evolutionary strategies, and their contributions to carbonate platform development during periods of environmental change.