Cretaceous Amber Insects
Amber — fossilized tree resin — is arguably the most spectacular medium for preserving insect fossils. While amber deposits occur at various points in geological history, the Cretaceous period produced some of the most important and diverse amber insect faunas known. Major Cretaceous amber deposits include Burmese amber (~99 million years old), Lebanese amber (~130 million years old), and deposits in France, Spain, Canada, and New Jersey.
What Has Been Found
The diversity of insects in Cretaceous amber is astonishing. Major groups represented include:
Hymenoptera (Ants, Wasps, Bees)
Cretaceous amber has yielded the oldest known ants (see Sphecomyrma), some of the earliest bees, and a wide diversity of parasitoid wasps. These fossils document the early diversification of the Hymenoptera, which today is one of the most species-rich insect orders.
Coleoptera (Beetles)
Beetles are abundant in Cretaceous amber, representing dozens of families. Many Cretaceous amber beetles are identifiable to modern families, showing that beetle diversity was already high by the mid-Cretaceous.
Diptera (Flies)
Flies are among the most commonly preserved insects in Cretaceous amber. Mosquitoes, midges, fungus gnats, and many other families are well represented. Some Cretaceous amber mosquitoes have been found with evidence of blood meals in their guts, though the DNA preservation seen in fiction is not supported by science.
Other Groups
Termites, thrips, barklice, aphids, scale insects, earwigs, and representatives of many other orders have been found in Cretaceous amber. Non-insect arthropods are also common, including spiders, mites, pseudoscorpions, and occasionally crustaceans.
Quality of Preservation
Amber preservation is exceptional because it captures insects in three dimensions, often with fine surface details like setae (hairs), color patterns, and even internal structures visible through the translucent medium. In some cases, parasites, gut contents, and pollen grains are preserved on or within the insect. See Amber as a Time Capsule for a detailed discussion of how amber preserves biological material.
Scientific Importance
Cretaceous amber insects are critical for understanding the mid-Cretaceous explosion of insect diversity, which is closely tied to the rise of flowering plants. The amber record provides a detailed snapshot of insect communities at a pivotal moment in evolutionary history, when the ecological relationships between insects and angiosperms were first being established.