India's recorded history of clothing goes back to the 5th millennium BC in the Indus Valley Civilisation where cotton was spun, woven and dyed. Bone needles and wooden spindles have been unearthed in excavations at the site. The cotton industry in ancient India was well developed, and several of the methods survive until today. Herodotus, an ancient Greek historian described Indian cotton as "a wool exceeding in beauty and goodness that of sheep". Indian cotton clothing was well adapted to the dry, hot summers of the subcontinent. Most of the present knowledge of ancient Indian clothing comes from rock sculptures and paintings in cave monuments such as Ellora. These images show dancers and goddesses wearing what appears to be a dhoti wrap, a predecessor to the modern sari.The upper castes dressed themselves in fine muslin and wore gold ornaments The Indus civilisation also knew the process of silk production. Recent analysis of Harappan silk fibres in beads have shown that silk was made by the process of reeling, a process known only to China until the early centuries AD.