The upper thermal limits for burrowing and survival were compared with micro-habitat temperature for anomalodesmatan clams: Laternula elliptica (Antarctica, 67°S); Laternula recta, (temperate Australia, 38°S) and Laternula truncata (tropical Singapore, 1°N). Lethal limits (LT50) were higher than burrowing limits (BT50) in L. elliptica (7.5-9.0 and 2.2°C) and L. recta (winter, 32.8-36.8 and 31.1-32.8°C) but the same range for L. truncata (33.0-35.0 and 33.4-34.9°C). L. elliptica and L. truncata had a BT50 0.4 and 2.4-3.9°C, respectively, above their maximum experienced temperature. L. recta, which experience solar heating during midday low tides, had a BT50 0.7-2.4°C below and a range for LT50 that spanned their predicted environmental maximum (33.5°C). L. recta showed no seasonal difference in LT50 or BT50. Our single genus comparisons contrast with macrophysiological studies showing that temperate species cope better with elevated temperatures. © Springer-Verlag 2009.