Chinese archaeologists have discovered the remains of rare species of ancient animals and plants which existed 8,000-4,800 years ago in the Dadiwan Historical Site in the eastern part of Gansu Province.
The site belongs to the New Stone Age and is located in a valley in the southeastern part of the Loess Plateau, a dry inland region in north China, according to the archaeologists.
"But in ancient times, the area had a mild climate, fertile soil and rich water resources, basic elements for diversified species."
Archaeologists said that the hundreds samples of xylanthrax of tree were found in the area, including fir, ash tree, nut-tree and cycad.
Relics from wooden houses of different historical periods were also unearthed in the area, indicating that there were vast natural forests.
The 1,700 pieces of animal bones excavated in the site belong to 28 species, including types of rhinoceros and antelopes which now only live in tropical or semitropical areas.
The ancient animals also include macaque, bear, tiger, elephant, leopard and even some clam species.