< There are a lot more on Dartmoor but they have to be Discovered by a Named archaeo before they are recognised! >
My god - if that's the case we'll be waiting years! The vast majority of rock-art in Yorkshire has been found, drawn, photographed & catalogued by us dedicated amateurs - NOT archaeologists. Ask Stan Beckensall!
Surely there's some decent Dartmoor doods amongst you willing to get out & start gathering the data - assuming they're there. A loada spurious 'bowls' and curious deep cups are one thing, we need the rings and other lines to make sure o' some good authenticity!