Extant and Fossil Sponges Associated with Hydrothermal Vent and Cold Seep Communities

Abstract

AbstractSponges are well known from recent vents and seeps, but most of them are background organisms that may occur elsewhere. Only a few are proven to be dependent on chemosynthesis. Conversely, sponges are only rarely reported from ancient hydrothermal vent and cold seep deposits. Here we present an overview of present-day sponges reported from such communities, as well as a review of all supposedly vent- and seep-associated fossil sponges reported so far. The most common sponges in the present-day seep and vent communities are Demospongiae, while Hexactinellida are rare. Most of these sponges are considered as “background” fauna with an exception of Cladorhizidae, which may thrive in deep-water hydrothermal vents. The oldest confirmed sponges from ancient seep sites are reported from the Late Jurassic of France and Jurassic/Cretaceous boundary beds in Svalbard. Additionally, we report herein new hexactinellids from Late Cretaceous localities in Japan. The Paleogene and Neogene records of seep sponges are more common but limited mostly to US Pacific Coast. Our review clearly shows that in the fossil record of chemosynthesis-based communities, sponges were equally common and diversified as they are today but were just overlooked.KeywordsCalcareaCambrianCladorhizidaeCretaceousDemospongiaeSponges (extant)Sponges (fossil)HexactinellidaHomoscleromorphaJurassicNeogenePaleogenePoriferaSeepsSpongillinaHydrothermal vents