A park ranger in south China has caught an enormous Chinese salamander that is the world's largest living amphibian and is known as the 'Living Fossil' because it has remained unchanged for 170million years. The man, named only as Mr Xiao, was shocked to find the rare giant salamander swimming in the water and later released it back into the wild, reported the People's Daily Online. Although it is one of the world's oldest species – dating back more than 170 million years – there are few surviving populations of giant salamander left in the wild. Its appearance has barely changed since the Jurassic period. Scroll down for video . Giant: The salamander found by Mr Xiao measured 83cm in length and weighed in at 5.5kg . Shock: Park ranger Mr Xiao could not believe his eyes when he saw the rare creature swimming in the river . The giant salamander, which measured 83cm in length and weighed 5.5kg, was found in Heyuan City in southern China's Guangdong Province. After keeping it in a temporary tank, Mr Xiao released the creature back into the river, watched by a crowd of fascinated tourists. The giant salamander is listed as 'critically endangered' on the International Union for Conservation of Nature (IUCN) Red List and a protected species in China. Prize catch: Mr Xiao shows off his discovery, the first of its kind to be found in the area . Fine specimen: The Chinese giant salamander is the world’s largest living amphibian and has been known to grow up to 1.8m long . Despite its status as an endangered species, it is still regarded a delicacy among China's super rich. The salamander population has declined drastically over the last 30 years due to poaching and destruction of its habitat. Earlier this year Chinese officials were investigated for reportedly eating a giant salamander at a luxury banquet in Shenzhen. A recent government crackdown means that anyone found to be eating endangered species could receive a jail sentence of up to ten years. Attention: A young boy enjoys his moment with the rare amphibian before it is returned to the wild. 30 years ago the giant salamander was relatively common . It is believed by some that the salamander has anti-ageing benefits, although there is no scientific evidence to support this. The giant salamander holds a treasured place in Chinese mythology and is called 'wa wa yu' - or 'baby fish' - in Chinese because its distress call sounds like the cry of a baby. In the past the amphibian could grow to more than 1.8 metres in length and over 50 kilograms in weight, but due to wild harvesting most salamanders today are much smaller.
Ranger was shocked to see the giant salamander while picking winkles . The ancient amphibian measured 83cm in length and weighed 5.5kg . The animal is  critically endangered on the Red List of threatened species . Known as a 'living fossil', it has barely changed since the Jurassic period . In China it is known as 'wa wa yu' - or 'baby fish' - because its distress call sounds like the cry of a baby .