Crystal Palace Park's dinosaurs are to join Buckingham Palace, the Royal Albert Hall and the Whitehall Cenotaph on a list of national treasures.

The 1850s animals sculptures, built in the grounds of the Crystal Palace after it was shifted there from the Great Exhibition in Hyde Park, and their surroundings are to be upgraded from Grade II heritage listing to Grade I.

Culture Minister Margaret Hodge said the sculptures would now join the other 2.5 per cent of treasures on the heritage listed in Grade I.

"The prehistoric animal sculptures and associated geological formations provide an insight into the mid-19th Century reconstruction of dinosaur species that had only recently been discovered," Mrs Hodge said.

"They are believed to be unique and are clearly of exceptional historic interest in a national and probably international context.

"I am delighted to upgrade their list entry to reflect their importance."

English Heritage describes the sculptures as "the first attempt to accurately reconstruct the three dinosaur species known to the scientific world in the 1850s within their geological environment".

They were designed by Benjamin Waterhouse Hawkins and were built out of brick and artificial stone on a framework of iron rods.

The lead mine were constructed at the same time by James Campbell an engineer and mineralogist.

Nationally, there are 372,905 entries on the heritage list with 9,137 at Grade I, 21,009 Grade II* and 341,894 Grade II.