Tree resin and water do not merge. Thus for a long time researchers have been wondering how come that water drops with trapped crustaceans and amoebas appeared in Polish amber. Now they managed to find an answer to this question. (Proceedings of the National Academy of Sciences)
The head scientist was Dr. Alexander Schmidt from the Berliner Museum of Natural History. We have gone back in time to ambergenic forests from 40 million years ago. From prehistoric conifers lots of resin drips. One of the drops meets a puddle on its way and falls into the water. In the pond float numerous organisms and one of them sticks to the surface of the gluey lump. Trying to free itself, it falls deeper and deeper inside of it and finally dies.
In summer the puddle dried and flood brought to the forest bottom residues, which allowed for good preservation of resin. With time it turned into amber.
Professor David Dilcher from the Florida Museum of Natural History worked with Schmidt. The gentlemen think that some water animals died as a result of being flooded with resin and some found themselves in a water drop absorbed by a tree’s secretion.
During realization of their research the German and American observed animals getting into resin in contemporary seaside mangrove forests east from Gainesville, Florida. With use of a saw they cut off pieces of bark from pine trees in order to cause resin to flow out. As soon as the drops fell into water, the scientists gathered them and checked under a microscope with great magnification what found itself in the lump.
It turned out that in resin there were representatives of entire local microfauna and flora, saprophytes, fragments of water plants, small crustaceans (ostracodes), ciliates and even bacteria and fungi, among others. The latter ones need water and that is why they developed until the drop dried and the resin itself finally solidified.
If it had been left in the puddle, the resin could transform into amber one day. First, however, the water level would have to drop so that the fluid could dry.
Schmidt gives some curiosities on amber as well. The oldest specimen containing some form of life is 220 million years old and it was found in the Dolomites, Italy. The oldest amber with an insect inside is “only” 130 million years old and comes from Lebanon.
Amber used for making jewelry is much younger, usually dated from between 50 and 15 million years ago.