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XI'AN, Sept. 20 -- A geological research team announced Friday that they had discovered groups of 100-million-year-old fossils of dinosaur footprints in northwest China's Shaanxi Province.

Researchers found a total of nine fossilized footprints, among which five were well-preserved, on purple sandstones in Jingbian County between June and July, according to the Shaanxi Institute of Geological Survey.

The study on the stratigraphy and morphology of the site unveiled that the tracks date back 100 million years to the Cretaceous Period, according to Xing Lida, an associate professor with China University of Geosciences (Beijing).

It is uncommon to uncover fossils of dinosaur footprints here in the desert area of northern Shaanxi, which may open a window for the research of the paleoclimate, paleogeography and stratigraphy in this region, Xing added.

Researchers will soon probe into dinosaurs' classification and sedimentary environment based on the footprints.