Spider in amber. Macrophotograph of a fossilized spider (at left) and fly embedded in Baltic amber. Amber is fossilized resin that was produced by various coniferous trees. The sticky resin trapped small insects and other animals as it solidified and hardened, preserving their bodies for millions of years. This is one of the few processes by which fossils are preserved complete with all of their soft tissues. Animals preserved in this way include various types of insect including mosquitoes, wasps and ants. Many of these species are now extinct.