Many trees produce resin, but usually it is broken down by physical and biological process. Exposure to weather tends to disintegrate resin, assisted by microorganisms such as bacteria and fungi. For resin to survive long enough to become amber, it must resist such forces, or be produced under conditions that exclude them.[1] Baltic amber (historically called Prussian amber) is found as irregular nodules in a marine sand, known as blue earth, in the Lower Oligocene strata of Sambia in Kaliningrad Oblast, where it is now systematically mined.[2] Agathis amber comes from the conifer Agathis, a tree that used to grow over a much wider area. Amber from America and Africa often comes from the Hymenaea protera, a genus of legume tree. Amber inclusions The resin can contain, in addition to the beautifully preserved plant-structures, remains of insects, spiders, annelids, frogs,[3] crustaceans and other small organisms that became trapped while it was fluid. In most cases the organic structure has disappeared, leaving only a cavity, with perhaps a trace of chitin.

lata , Eocene 1. Introduction It has been estimated that over 10 5 tons of Baltic amber were produced by Palaeogene forests in the pan-Tethyan region of northern Europe, making this the largest single known deposit of fossilized plant resin ( Poinar 1992 ; Grimaldi 1996 ; Weitschat & Wichard 2002 ). Baltic amber contains the most diverse assemblage of fossil insects of any age, which are typically preserved in exquisite anatomical detail ( Grimaldi & Engel 2005 ). The cultural and economic significance of Baltic amber should not be understated: it has been recognized as a luxury item in archaeological contexts as old as Palaeolithic, and subsequently became the basis for important trade routes in Roman and Medieval times ( Spekke 1957 ). Baltic amber is still mined and traded actively, with large intact blocks and specimens containing entombed insects commanding the highest prices. However, Baltic amber is never found in its original stratigraphic position, having been redeposited in Eocene glauconitic marine sediments as well as Neogene fluvial and glacigenic deposits. Although Baltic amber has been linked to resin production in forests dominated either by the conifer family Araucariaceae ( Langenheim 1969 ; Gough & Mills 1972 ; Mills et al . 1984 ) or Pinaceae ( Conwentz 1890 ; Schubert 1961 ; Weitschat & Wichard 2002 ), neither group fully satisfies the range of geochemical and phytogeographical criteria necessary for a conclusive linkage, resulting in a botanical conundrum that has endured for well over a century. A detailed review of the ‘Tertiary Baltic amber mystery’ is provided by Langenheim (2003) . Amber is polymerized from a broad range of isoprenoid compounds originally produced by plant secondary metabolism. These compounds include primarily terpenoids, carboxylic (resin) acids and associated alcohols. Terpenoids constitute the most diverse group of plant natural products, with approximately 25 000 known compounds ( Croteau et al . 2000 ). These are pro