Supplementary Information 1. List of all non-meiofaunal taxa collected from the three vent fields, with Field Museum catalogue numbers, and number of individuals (n) for gastropod taxa.
Main Endeavour Field: Palm Springs Vent ROPOS Dive HYS 346 13-14 August 1996.
Gastropoda: Lepetodrilus fucensis (FMNH 279666; FMNH 279670) n = 3702 (90.76% of total gastropod fauna)
Provanna variabilis (FMNH 279668; FMNH 279669) n = 25
Depressigyra globulus (FMNH 279664; FMNH 279671) n = 344
Clypeosectus curvus (FMNH 279665; FMNH 279672) n = 7
Hyalogyrina globularis Warén and Bouchet, 2001 (FMNH 279661) n = 1
Buccinum thermophilum Harasewych and Kantor, 2002 (Tunnicliffe Lab) n = 3
Polychaeta: Amphisamytha galapagensis Zottoli, 1983 (FMNH 5635)
Lepidonotopodium piscesae Pettibone, 1988 (FMNH 4023; FMNH 4032) Ophryotrocha globopalpata Blake and Hilbig (FMNH 4024)
Paralvinella palmiformis Desbruyeres and Laubier, 1986 (FMNH 4035; FMNH 4017; FMNH 4029; FMNH 5636)
Paralvinella pandorae Desbruyeres and Laubier, 1986 (FMNH 4034; FMNH 4022; FMNH 4021)
Ridgeia piscesae Jones, 1985 (FMNH 4033; FMNH 4018; FMNH 4019)
Spionidae (FMNH 4015)
Crustacea: Cirripedia (FMNH 4025)
Main Endeavour Field: Easter Island ROPOS Dive HYS 350 16-17 August 1996.
Gastropoda: Lepetodrilus fucensis (FMNH 279673) n = 828 (93.98% of total gastropod fauna)
Provanna variabilis (FMNH 279676) n =3
Depressigyra globulus (FMNH 279675; FMNH279680) n = 49
Buccinum thermophilum (FMNH 279674) n = 1
Pycnogonida: Ammothea verenae Child, 1988 (FMNH 4041)
Polychaeta: Lepidonotopodium piscesae Pettibone, 1988 (FMNH 4038)
Paralvinella palmiformis Desbruyeres and Laubier, 1986 (FMNH 4039)
Paralvinella pandorae Desbruyeres and Laubier, 1986 (FMNH 4040)
Ridgeia piscesae Jones, 1985 (FMNH 4037)
Clam Bed ROPOS Dive HYS 351 17-18 August 1996.
Gastropoda: Lepetodrilus fucensis McLean, 1988 (FMNH 279643; FMNH 279684) n = 1297 (36.14% of total gastropod fauna)
Provanna variabilis (FMNH 279686; FMNH 279640; FMNH 279648) n = 281
Depressigyra globulus FMNH 279649; FMNH 279641; FMNH 279685 n = 1917
Buccinum thermophilum Harasewych and Kantor, 2002 (FMNH 279654) n = 14 (egg clusters FMNH 279655l; FMNH 279654)
Clypeosectus curvus McLean, 1989 (FMNH 279650; FMNH 279642) n = 74
Hyalogyrina globularis Warén and Bouchet, 2001 (FMNH 280923; FMNH 279656)
n = 2
Temnocinclis euripes McLean, 1989 (FMNH 279657; FMNH 279652) n = 4
Bivalvia: Calyptogena sp. (FMNH 279658; FMNH 279653; FMNH 279644; FMNH
279645)
Bivalvia (FMNH 279659)
Polychaeta: Hesiospina vestimentifera Blake, 1985 (FMNH 5633)
Lepidonotopodium piscesae Pettibone, 1988 (FMNH 4002)
Levensteiniella kincaidi Pettibone, 1985 (FMNH 5634)
Paralvinella palmiformis Desbruyeres and Laubier, 1986 (FMNH 4003)
Protomystides verenae Blake and Hilbig, 1990 (FMNH 4004)
Ridgeia piscesae Jones, 1985 (FMNH 4000; FMNH 4001)
Scoloplos sp. (FMNH 4010)
Spionidae (FMNH 4016)
Sipuncula: Sipuncula (FMNH 4011)
Crustacea: Macroregonia macrochira Sakai, 1978 (FMNH 4014)
Munidopsis alvisca Williams, 1988 (FMNH 4007)
Pycnogonida: Ammothea verenae Child, 1988 (FMNH 4006)
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