Chen Penbin runs in Nantong, Jiangsu province, on May 26, 2015. [Photo/CFP]

BEIJING -- 88 is considered a lucky number by the Chinese and in his 88th marathon in as many days, China's ultra-marathon runner Chen Penbin revisited the Jurassic period.

On the misty and cloudy Sunday morning, Chen, darker and bearded, ran through the fossil wood park in northwest Beijing. The silicified wood here is dated back to the Jurassic period and scientists already discovered foot prints fossils of dinosaurs in the mountains.

It took Chen four hours, seven minutes and 57 seconds to finish the run and there are just 12 to go to reach his goal.

As China's first international ultra-marathon champion, Chen planned to run 100 marathons in 100 days, embarking on his journey from Guangzhou in southern China on April 2 and is set to wrap up his odyssey in the capital Beijing in the country's north on July 10.

His journey is not by any vehicle but entirely on foot.

Chen, a former fisherman, wants to demonstrate that persistence is the way to success.

He found out that he possesses extraordinary stamina in a county push-up contest and he started to take part in all kinds of stamina events.

He completed a feat of running ultra-marathons in all seven continents.