Crustaceans in Cold Seep Ecosystems: Fossil Record, Geographic Distribution, Taxonomic Composition, and Biology

Abstract

AbstractNumerous crustaceans such as ostracods, decapod crustaceans, and some barnacles inhabit modern cold seep ecosystems, but little is known about their fossil record in these chemosymbiotic-based ecosystems. Consequently, their importance in structuring faunas at these biodiversity hotspots on the sea floor is poorly known, including to what extent seeps acted as refuges from extinction, the timing of occupancy of cold seeps, the degree of endemism, depth preferences, and the longevity of crustacean lineages. We provide the first synthesis of crustaceans in ancient seeps and show that they have been found in each continent due to a rapid increase in research since the 1990s. Ostracods and barnacles are known from body fossils alone. Conversely, decapods are represented by two types of fossils: body fossils primarily attributed to true crabs and ghost shrimps and their traces such as coprolites, repair scars, and burrows. The last ~150 million years saw a remarkable rise in the number of localities and occurrences of seep crustaceans, mostly caused by the diversification of decapods in a variety of environments including seeps. Although considerable progress was made in 30 years, the relatively unexplored fossil record of seep crustaceans provides ample opportunities for further taxonomic, macroevolutionary, and paleoecological research.KeywordsArthropodaAxiideaBarnacleBrachyuraBurrowCirripediaCoproliteCrustaceaDecapodaMethane seepOstracodaRepair scarTrace fossil