Tiny fragments discovered in China have just overturned the history of amber. At about 385 million years old, they are the oldest chemically confirmed example. This discovery pushes back the previous record by 65 million years.
The samples come from the Hujiersite geological formation in Xinjiang, northwestern China. They were enclosed in a coal layer from the Middle Devonian. Their age was established notably through the geological context and neighboring fossil spores.
Photographs of Hujiersite amber, dated to the Middle Devonian.
The fragments, embedded in coal or isolated, measure between 0.1 and 1.35 mm. They display different colors, transparencies, and sometimes different bubbles. Under ultraviolet light, one of them produces a strong blue fluorescence.
Amber forms when plant resin is preserved and then progressively transforms during fossilization. Plants generally produce this substance to heal their wounds. It can also protect them against certain microbes or harmful organisms.
In this case, the fragments remain microscopic. They are therefore too small to contain insects or other visible organisms, unlike more recent pieces of amber. Their scientific interest lies mainly in their age and chemical composition.
The researchers analyzed this composition using several techniques. The results show a resin rich in terpenic compounds. Its signature is more reminiscent of conifers than of flowering plants, even though these groups did not yet exist.
The plant that produced this resin, however, could not be identified. No fragment was directly associated with recognizable plant tissue. Scientists notably suggest progymnosperms or tree-like lycophytes, which were very present in the landscapes of the time.
The Devonian marks a major stage in the evolution of continents. Plants were growing, developing wood, and forming deeper root systems. Gradually, these transformations favored the emergence of the first large forests.
The discovery therefore indicates that resin production appeared very early in the history of land plants. This chemical defense may already have served against injuries, infections, or certain environmental stresses.
Until now, the oldest known amber dated to about 320 million years ago. These new fragments considerably extend this timeline. They also show that ancient plants already had relatively elaborate protective mechanisms.