About 99 million years ago, a tiny juvenile frog in what is today Myanmar was suddenly trapped in sap with a beetle, perhaps its intended next meal.
Judging from all the amber pieces, they discovered that the rainforest in question was situated somewhere near a beach.
The ambers which encaptured the frogs also contains traces of plants, mollusks, spiders, and other insects, and for Blackburn and Xing they are like time traveling thanks to the massive amount of information these fossils could offer about how was the animals' lives about 200 million years ago.
Dr Xing also explained to MailOnline that those rare fossils were from a new species that had been unknown to scientists before. It seems that the frog has not changed much for millennia. The other fossils contain two hands and an imprint of a frog that probably decayed inside the amber.
The discovery of a perfectly preserved frog inside amber fills an important gap in our understanding of tropical frog evolution.
However, Electrorana was the most well-preserved of the bunch with recognizable features including a skull, forelimbs, part of a backbone and a partial hindlimb, all measuring less than an inch.
The frog is believed to be a young frog less than two years old, judging by the fact that some of the bones in its ears and around its wrists had not been fully developed, said another member of the research team Edward Stanley.
However, Blackburn noted that small animals living in tropical forests have a very low chance of leaving behind fossils, which makes it hard to study their ancient history.
The fantastic fossil and species descriptions were published today in Nature's Scientific Reports.
The Dexu Institute of Paleontology in Chaozhou acquired the frog specimens as donations from private Chinese fossil collectors.
"It's nearly unheard of to get a fossil frog from this time period that is small, has preservation of small bones and is mostly three-dimensional", the study's co-author David Blackburn, the associate curator of herpetology at the Florida Museum of Natural History, said in a statement. He said his role in the project was to scan and describe the fossils. This discovery is a big deal because fossils of forest amphibians are rare, and because scientists haven't been sure when frogs first started to venture into tropical habitats. The frog was named Electrorana limoae. "Electrorana" is a combined word of "amber" and "frog" in Latin; while "Limoae" pays tribute to Li Mo, the amber collector who gave the largest gemstone to the scientists. But these are Eurasian species that live in temperate, not tropical, ecosystems.
"Frogs are common animals to encounter in the wet tropical forests of today, and easily more than a third of the almost 7,000 species of frogs live in these wet forests".
'While frogs today live throughout the wet tropics, we have little evidence of this association from the fossil record'.
Humid and hot northern Myanmar is renowned for its deposits of amber.