Frozen in time

Time is another important metric for evolution. This has prompted Chen to collect amber, which often contains samples of life forms from ancient eras.

One of his prized pieces is a 22 million-year-old chunk that contains a shrimp, which he bought in Mexico around 2016.

"At first, it looked like it was just a black stone, but after I polished it, the amber appeared. I felt like I'd just won a 100 million yuan ($13.9 million) lottery prize," Chen recalls.

It's the only amber specimen to be discovered with a real shrimp and heralds the finding of a previously unknown species.

Chen and his colleagues published the results of their research about the piece of amber in the academic journal, Science Bulletin, in 2021.

It is particularly precious since the shrimp had to be out of the water and somehow end up trapped in resin in order to be preserved in the amber, which is a very rare scenario, Chen says.

He has collected a lot of amber and put it on display in an insect museum in his hometown of Sanming, Fujian province.

"Amber is like a time capsule left by nature, and offers the only three-dimensional historical images of many ancient insects. It solidifies moments that have occurred on Earth. Through them, we can catch a glimpse of what has happened on this planet," says Chen.

"This is particularly fascinating."

Contact the writer at wangru1@chinadaily.com.cn