YORKSHIRE folk's skulls dramatically and inexplicably changed shape a few centuries ago, archaeologists have discovered.

Research by English Heritage has confirmed that Yorkshire men were not so much big heads as "round heads" in early medieval times - and the findings have left boffins baffled.

Studies of nearly 700 skeletons from the ruined church of St Martin's and its graveyard, in the deserted village of Wharram Percy, near York, has revealed a puzzling shift in men's skull shapes between the 11th and 13th centuries.

Before 1000AD, men had longer, narrower heads, and the same is true after 1200AD.

But between those dates, men's heads were, bizarrely, rounder. Stranger still, women's heads didn't change.

This anatomical "blip" has been spotted at other sites across Western Europe, but the Wharram data can be accurately radio carbon dated, and the change can be traced through a single, indigenous community.

Previous attempts to explain the odd phenomenon have linked the change with an influx of immigrants - such as Norse or Norman - introducing different racial characteristics.

But unfortunate Wharram, which lies south-east of Malton, was an isolated and dwindling population that was crippled by plague and sheep blight. Newcomers gave it a wide berth and it was eventually doomed.

English Heritage human skeletal biologist Simon Mays said: "Our work has yielded few clues on why skulls changed, but we have cast serious doubt on some of the current theories. Despite the best efforts of science, we're still in the dark as to why it happened.

"Another possible cause is climate change, because people in cold climates generally have rounder heads. But Wharram was actually warmer in medieval times than it is today.

Mr Mays added: "Perhaps the plague could have been a factor, since it struck across Western Europe, but at this stage that's little more than a guess."


Wharram Percy, deserted village

The site near Malton is the best preserved of Britain's 3,500 deserted villages, and it is managed by English Heritage.

Archaeological excavations at the village have been going on for decades, and will eventually produce 14 volumes of research. Other findings include:

* The proportion of left-handed people in medieval times was higher than it is now: around 15 per cent compared with eight per cent today* Although infant mortality was high by modern standards, it was low compared to other historic populations* Villagers were more vulnerable to diseases due to their isolation than poor city folk in York.

Wharram Percy is six miles south-east of Malton, off the B1248, and is open during the day. Entry is free. For more details, visit www.english-heritage.org.uk