'No evidence' Stonehenge bluestones quarried
7 December 2015 Last updated at 13:19 GMT
There is "no evidence" some of the stones at Stonehenge that came from two Pembrokeshire quarries were excavated by man, a geologist has said.
Dr Dyfed Elis Gruffydd has disputed research, led by University College London (UCL), which found the bluestones came from outcrops at Carn Goedog and Craig Rhos-y-felin.
Following excavations, the team of archaeologists and geologists said the stones may have been first used in a local monument near the quarries and then dismantled and taken to Wiltshire.
But Dr Gruffydd said no evidence of human quarrying had been found at the sites.