In the evening breeze on a stony hilltop a day’s drive south of Mumbai, Sudhir Risbud tramped from one rock carving to another, pointing out the hull of a boat, birds, a shark, human figures and two life-size tigers.
“They’re male,” he said with a smile, noting that the carver had taken pains to make the genitalia too obvious to ignore. He was doing a brief tour of about two dozen figures, a sampling of 100 or so all etched into a hard, pitted rock called laterite that is common on the coastal plain that borders the Arabian Sea.
The carvings are only a sample of 1,200 figures that Mr. Risbud and Dhananjay Marathe, engineers and dedicated naturalists, have uncovered since they set out on a quest in 2012. The two men are part of a long tradition of amateur archaeologists, according to Tejas Garge, the head of the Directorate of Archaeology and Museums for the state of Maharashtra, and the petroglyphs they have uncovered amount to a trove of international significance.
There are no depictions of bulls, so it is pre-agricultural. Additionally, some of the animals depicted disappeared from the area in the later Pleistocene. That means the carvings could date to people who lived in the area between 40,000 and 20,000 years ago, right up to the Last Glacial Maximum.