An accidental archive
In the ancient city of Tissamaharama, once the capital of the Kingdom of Ruhuna, archaeologists found an unusual record of the past. Within soil layers dating from approximately 200 BCE to 100 CE, they discovered large, compressed cakes of elephant dung. The area's waterlogged conditions, created by an extensive irrigation system of reservoirs, prevented oxygen from decomposing organic materials. This anaerobic environment preserved the dung for two millennia, trapping a record of the local ecosystem.
These are preserved organic matter, not preserved organic matter, soft enough to be carefully dissected. Excavations led by the German Archaeological Institute and Sri Lanka's Department of Archaeology unearthed these deposits within the ancient city's citadel. The dung provides a direct sample of what these megaherbivores were eating. Because elephants are generalist feeders, their diet gives a broad survey of the plants available in the landscape surrounding the settlement. The dung cakes are a biological archive, helping scientists to reconstruct the local environment and understand its interaction with a major urban center.
Reading the seeds
Analysis of the dung, a field known as archaeobotany, revealed a mixture of seeds from wild, managed, and domesticated plants. Scientists, including archaeobotanist Dorian Fuller, identified grains of cultivated rice (Oryza sativa), indicating the presence of nearby paddy fields fed by Tissamaharama's sophisticated irrigation networks. The findings also included seeds from fruit trees and various wild grasses and herbs. This combination shows a complex area shaped by human activity.
The ancient city was not an isolated urban zone but was integrated with a managed environment. Inhabitants practiced wet rice farming, maintained fruit groves, and foraged for wild plants. The elephants, moving through these different zones, consumed plants from each and deposited the undigested seeds together. This paleo-ecological data confirms that by the late centuries BCE, the people of Tissamaharama were active ecological engineers, creating a diverse agricultural area that both sustained a large population and existed alongside wild spaces.