Abstract:
The paleoecological context of hominin occupation in South Asia during the early and middle Pleistocene is
virtually unknown. Attirampakkam, India, is an archeological site of global importance, with an early Acheulian
occupation (age bracket of ~1.07–1.77 Ma) succeeded by Middle Paleolithic levels. Here we report on the
recovery of phytoliths from artifact-bearing Quaternary deposits in excavated trenches. We focus on the reconstruction
of past vegetation during hominin occupation of the site. The present study provides information on
hominin microenvironments and local habitats in South Asia, situating them in a more tangible ecological
context than so far achieved. Results show that this region was arid during the earlier stages of the early
Pleistocene, and was occupied by hominins living in a landscape locally lacking woody plants. Herbaceous
vegetation was dominated by C4 Chloridoid grasses. In the later phase of the early Pleistocene, the landscape was
wooded and dominated by C4 Panicoid grasses, with a significant reduction of C4 Chloridoid grasses indicating a
shift from a drier to a relatively more humid climate. A diverse husk and leaf phytolith assemblage of wild Oryza
spp. (rice) occurring as natural annual or perennial components of the vegetation in the area, other herbaceous
plants such as Cyperaceae (sedges), and the continuous presence of blackened phytoliths, suggest the establishment
a grassland landscape with enclaves of wetland habitat affected by seasonal flooding and frequent fires.
The transition from the early to the middle Pleistocene was marked by a moderately humid climate, with a shift
toward aridity during the late Pleistocene, during which we note an environment dominated by C4 Chloridoid
grasses, by a sharp reduction of C4 Panicoid grasses, and by a rise in woody taxa. During the middle to late
Pleistocene, Middle Paleolithic populations would have witnessed water bodies near the site, as reflected by the
presence of plants adapted to swampier conditions such as Cyperaceae and Oryza spp. The archeological record
terminates in Layer 1, when human occupation decreased drastically, possibly because of increased aridity and/
or greater environmental variability. The phytolith fingerprint at ATM sheds light on the co-occurrence of,
vegetation, fire and early prehistoric land occupation. An important aspect is the evidence of Oryza spp., suggesting
that wild rice occurred in the environment frequented by these early hominins.
