Amber is a unique and highly effective preservative of fossils. It is formed from the hardened resin of ancient trees, primarily from coniferous trees. Here’s how fossils are preserved in amber:
- Formation of Resin:
- Trees produce resin as a defense mechanism against injury, infection, or insect activity.
- When a tree is damaged or wounded, resin is released and oozes out of the tree, forming sticky droplets or flows.
- Entrapment of Organisms:
- Small organisms, such as insects, spiders, or small plant parts, can become trapped in the sticky resin.
- The resin acts like a natural adhesive, immobilizing the organism and preventing decay.
- Preservation Process:
- Over time, the sticky resin hardens and undergoes polymerization, transforming into amber.
- The hardening process can occur through the loss of volatile components, oxidation, or the influence of heat and pressure from geological processes.
- Encasement in Amber:
- The resin completely encases the trapped organism, forming a protective amber shell around it.
- The amber preserves the organism in incredible detail, capturing its external morphology, delicate structures, and sometimes even the internal organs.
- Long-Term Preservation:
- Amber provides a nearly airtight and chemically stable environment, protecting the enclosed organism from decay and decomposition.
- The organism remains suspended in time, essentially unchanged for millions of years.
The exceptional preservation offered by amber allows scientists to study the morphology, behavior, and ecology of ancient organisms with remarkable detail. In addition to insects, other small organisms like spiders, mites, small vertebrates, plant fragments, and even microscopic organisms can also be found preserved in amber. The study of amber fossils, or “inclusions,” provides valuable insights into the biodiversity, paleoecology, and evolutionary history of ancient ecosystems.