Amber as a Time Capsule
Amber — fossilized tree resin — is the most spectacular preservation medium for insect fossils. Unlike compression fossils, which flatten organisms into two-dimensional impressions, amber captures insects in full three dimensions, sometimes preserving fine surface details like setae (hairs), scales, color patterns, and even internal tissues.
How Amber Forms
The process begins when a living tree produces resin, a sticky, viscous substance that flows from wounds in the bark. When a small insect walks or flies into fresh resin, it becomes trapped. Additional resin flows cover the insect, encasing it completely. Over time, the resin hardens through the loss of volatile compounds and chemical polymerization. If the hardened resin is then buried in sediment and subjected to heat and pressure over millions of years, it undergoes further chemical changes to become true amber — a stable, fossilized material.
What Gets Preserved
Amber can preserve the external morphology of an insect in extraordinary detail: compound eye facets, individual wing veins, leg spines, antennal segments, and surface microsculpture are often clearly visible. In some cases, internal structures are also preserved — muscles, gut contents, reproductive organs, and parasites living inside or on the host insect. Behavioral snapshots are occasionally captured: insects mating, carrying prey, tending eggs, or being parasitized.
What amber does not generally preserve is DNA, despite the premise of Jurassic Park. While early studies claimed to extract DNA from insects in amber, these results have not been replicated and are now considered to be contamination artifacts. The oldest verified ancient DNA comes from permafrost samples less than a million years old, far younger than any amber deposit. However, some original proteins and chitin structures may persist in amber under certain conditions.
Major Amber Deposits
The most important amber deposits for prehistoric insects include Burmese amber (~99 Ma), Lebanese amber (~130 Ma), Baltic amber (~44-34 Ma, Eocene), Dominican amber (~20-15 Ma, Miocene), and various smaller deposits in France, Spain, Canada, and elsewhere. The Cretaceous-age deposits are most relevant to this site, as they capture insect communities from the age of dinosaurs.
Amber vs. Copal
Not all fossilized resin is true amber. Copal is younger, less polymerized resin (typically less than a few million years old) that is softer and more soluble than amber. Copal also preserves insects but is less stable over geological time. The distinction between amber and copal is important because some commercially available "amber" with insect inclusions is actually copal or even artificial forgeries. Researchers use physical and chemical tests (such as solubility in solvents and infrared spectroscopy) to verify that specimens are genuine amber.