Experts from China and Greece have started a new round of joint preservation work on more than 180 fossilized dinosaur footprints discovered in a suburb of Beijing.

The team has started to clean the surface of the fossils, fill the cracks and apply a special reagent to prevent them from weather damage.

"We hope that our preservation work can make dinosaur footprints more visible and maintain their original conditions, so as to attract more visitors and enrich their knowledge about dinosaurs," said Ilias Valiakos, an expert from Greece.

The footprints, unearthed in a geological park in Yanqing County in 2011, are the first dinosaur traces to be found inside the city. They are believed to be left by dinosaurs that lived some 140 to 150 million years ago in the late Jurassic Period.

"About 120 footprints are relatively visible, with the largest ones 60 cm long and 3 cm deep," said Zeng Guangge, an administrator with the Yanqing Geopark.

The team has conducted two rounds of preservation work on these dinosaur footprints in October last year and May this year.