Search

The Sibay and Yaman Kasy massive sulphide deposits contain macrofossil assemblages that represent some of the oldest known hydrothermal vent communities. The deposits are hosted respectively by Middle Devonian and Silurian arc-related volcanic rocks in the Ural Mountains of Russia, and formed under the same environmental constraints as modern vent sulphides. The Sibay palaeocommunity comprises, in order of decreasing abundance, tubes of an indeterminate ?annelid and the vestimentiferanTevidestus serrriformisShpanskaya, Maslennikov and Little and articulated specimens of the modiomorphid bivalveSibaya ivanovigen. et sp. nov. The Yaman Kasy palaeocommunity comprises, in order of decreasing abundance, tubes of the ?polychaeteEoalvinellodes annulatusgen. et sp. nov. and the vestimentiferanYamankasia rifeiaShpanskaya, Maslennikov and Little, and specimens of the ?kirengellid tergomyanThemoconus shadlunaegen. et sp. nov., the lingulate brachiopodPyrodiscus lorrainaegen. et sp. nov., an indeterminate vetigastropod, and the ambonychiid bivalveMytilarcasp. Some of these taxa have affinities to endemic taxa at modern hydrothermal vent sites and some belong to taxa that are typical of Palaeozoic non-vent marine palaeocommunities. Therefore, there has been movement of taxonomic groups in and out of the vent ecosystem through the Phanerozoic. [ABSTRACT FROM AUTHOR]