By Rebecca Morelle
BBC News science reporter
Researchers have found that the shape of the human skull has changed significantly over the past 650 years.
Our ancestors had more prominent features but lower foreheads
Modern people possess less prominent features but higher foreheads than our medieval ancestors.
Writing in the British Dental Journal, the team took careful measurements of groups of skulls spanning across 30 generations.
The scientists said the differences between past and present skull shapes were "striking".
The team used radiographic films of skulls to record extensive measurements taken by a computer.
They looked at 30 skulls dating from the mid-14th Century. They had come from the unlucky victims of the plague. The skulls had been excavated from plague pits in the 1980s in London.
Another 54 skulls examined by the team were recovered from the wreck of the Mary Rose which sank off the south coast of England in 1545.
All the skulls were compared with 31 recent orthodontic records from the School of Dentistry in Birmingham.
The two principal differences discovered were that our ancestors had more prominent features, but their cranial vault - the distance measured from the eyes to the top of the skull - was smaller.
Dr Peter Rock, lead author of the study and director of orthodontistry at Birmingham University, told the BBC News website: "The astonishing finding is the increased cranial vault heights.
"The increase is very considerable. For example, the vault height of the plague skulls were 80mm, and the modern ones were 95mm - that's in the order of 20% bigger, which is really rather a lot."
He suggests that the increase in size may be due to an increase in mental capacity over the ages.
The study of human remains has previously fallen into controversy, and a report commissioned by the UK government called for human remains to be repatriated where possible.
The ancient skulls used in this study, from which the radiographic films were taken, have either been reburied or are now housed in museums.
Professor Robert Foley is director of the Leverhulme Centre for Evolutionary Studies at Cambridge University, and sat on a government working group which has drawn up guidelines on working with human remains.
"The study of human remains can provide vital information about our past. There is a huge interest in our biological past - both from an evolutionary and a historical point of view - and research into human bones can tell us a great deal," he said.
"This new research shows how bones, and even the records of bones, can provide more knowledge to the scientific community, and ultimately the public."