Are Hydrothermal vent animals living fossils

Since their discovery in 1977, hydrothermal vent com-munities have provided many surprises about life in the deep sea and in extreme environments. It has been suggested that vent communities contain many living fossils and that deep-sea chemosynthetic environ-ments, such as vents and hydrocarbon seeps, are buffered from extinction events that affect the photic zone. This hypothesis is based on the dependence of these deep-sea communities on a geochemical energy source and the considerable levels of taxonomic novelty that they contain. Here, we review recent evidence from the fossil record of hydrothermal vents and hydro-carbon seeps, together with molecular phylogenies of several dominant hydrothermal vent and seep taxa. In spite of significant discrepancies between the fossi