Archaeology and ecology of acavus snails in Sri Lanka’s semi-arid to intermediate zones: uncovering holocene microclimatic changes

Abstract This study presents a discovery of Acavus haemastoma , wet-humid favouring arboreal land snails from Semi-Arid coastal lagoon habitat during the late Holocene period in Southern Sri Lanka, occurring around the mid-4th millennium BP. These findings challenge established notions regarding palaeoecological conditions within the Semi-Arid and Transitional Zones (SATZ), prompting a re-evaluation of prevailing archaeological assumptions. We propose that the presence of Acavus sp. in the SATZ is primarily attributed to their natural behaviours rather than anthropogenic influences. In conjunction with an examination of early archaeological literature, we explore the implications of humid phases within the SATZ, aligning these phases with Acavus snails’ distribution patterns and climatic fluctuations and proposing the value of land snails in Sri Lanka as a potential proxy for small scale micro-climatic conditions.