Taphonomy, fauna, environment and ecology of Upper Sivaliks (Plio-Pleistocene) near Chandigarh, India

Abstract

The fossil fauna of the molassic Sivalik deposits is well documented but little is known of its environment and ecology. Initial reports^1–8 were based on published fauna and flora, and palaeoecologically oriented field studies^9–13, particularly of the Upper Sivalik Subgroup, were few. We present here a preliminary report on the fauna, flora, taphonomy, environment and ecology of Upper Sivaliks of north-east Chandigarh, India. Previously these have yielded cercopithecoids, Procynocephalus¹⁴ and Theropithecus¹⁵, and Palaeolithic artefacts^16,17. We found that the Upper Sivaliks are basically fluviatile. The Tatrots and Pinjors were laid down by laterally shifting rivers on a flood plain. The Boulder Conglomerates are predominantly alluvial fan deposits. The Upper Sivalik bone assemblage is highly sorted with the dominance of heavier, denser and more durable parts. The fauna and flora indicate a mosaic dominated by wooded grassland with bushland and grassland for Tatrots and dominant grassland with some bushland and wooded grassland for Pinjors. The geology and fauna indicate that the climate was warm and humid during Tatrots, relatively arid and less warm during Pinjors, and became increasingly cold and arid during Boulder Conglomerate deposition in this area.