The research by experts from Nottingham University also revealed that the oldest known timbers in the "Ship of the Fens", in the west tower turrets, date back almost 1000 years to 1043-1068.

The team has been collecting samples of oak timbers from the cathedral and monastic buildings on the site for nearly two decades.

An initial programme of sampling was undertaken between 1989 and 1996, funded jointly by the cathedral and English Heritage.

In 2001, English Heritage financed a further study with a viewing to dating structures which had previously not been assessed.

Derek Hamilton, scientific dating specialist at English Heritage, said: "During the 1980s and 1990s, when recording work started, we realised that Ely Cathedral was one of the best-preserved monastic complexes in the country.

"We then commissioned this more comprehensive study, which has not only enhanced our overall understanding of these buildings, but has ultimately provided important evidence for the likely timing of the 15th century earthquake."

It has also been discovered that timbers from the cathedral, Prior's Complex and Infirmary Complex range in date from the 11th century through to the late 18th century, with the research also providing evidence of where the wood originated.

Jane Kennedy, surveyor of the fabric for the cathedral, said: "From the smallest details discovered, we can start to build up a picture of the development of this vast and well-preserved site.

"The reports on the cathedral and monastic buildings have also enhanced our understanding of the timber trade, showing that the requirements for boards were such that timbers were procured from increasingly distant sources during the 14th and 15th centuries.

"For example, the very thin timbers, used for boarding, were imported mostly likely from the Baltic states, which provides information about the timber trade and the role of King's Lynn as an important port.

"Huge amounts of timber were needed in the construction of these magnificent buildings, and with very little available in the surrounding fens which were still flood plains, it all had to be sourced from outside the local area."

The original monastery at Ely was founded by St Etheldreda in 673.

Sauropods were the largest animals that lived on Earth. With their long necks, massive tails, small heads and stout legs they weighed on average about 20 tons and measured 20 yards in length. The biggest grew to 80 tons and were as long as 40 meters.

By contrast, the new dwarf species, called Europasaurus, was a mere 1 ton and about 6 yards long--about the size of a small rhinoceros or a big buffalo.

"This one is minute but it is still a big animal," said Sander, who reported the finding in the journal Nature.

The bones were discovered in marine beds in northern Germany. During the Jurassic period, sea levels were much higher than today, so much of central Europe was underwater.

Dwarfism is a common phenomenon on islands. The scientists believe the animals' size decreased because they lived in an area where sea levels rose and land masses shrunk.

Another possibility is that they moved as large animals to islands and shrank within a few generations because of limited resources.

Their small leg bones had led scientists to believe they were young dinosaurs, until a technique called bone microstructure revealed they were adults.

Sander and his team, who are one of only four groups worldwide who use the technique to study dinosaurs, took cores from the leg bones to determine the age of the dinosaurs.

"The microstructure of the bone is really well preserved. You can see where the cells were and the blood vessels," he said.

By comparing the size of the bones of the dwarf dinosaurs with their closest ancestors and descendants, the scientists determined how old they were.

The smallest upper leg bone they analyzed was 6.3 inches in length and the biggest 20 inches. Dwarf dinosaurs with 20-inch leg bones were fully grown, but in other species that would have represented a young animal.

Their closest relatives had femurs measuring 1.5 to 2 yards, according to the scientists.