Found in central India, these cupules (circular hollows on rock surfaces) are among the earliest known forms of rock art. They were likely created by a species like Homo erectus or Homo heidelbergensis and not Homo sapiens. Homo sapiens are not known to be in India until around 40,000 years ago. Homo erectus is known in India as early as 1.7 million years ago and Homo heidelbergensis around 300,000 years ago. If Homo heidelbergensis is confirmed, that moves the evolution of symbolic thought back to before 700,000 years ago. If Homo erectus is confirmed, that moves it back to well before 2 million years ago.