Here, we report the first discovery of Antarctic fossil resin (commonly referred to as amber) within a ~5 cm-thick lignite layer, which constitutes the top part of a ~3 m-long palynomorph-rich and root-bearing carbonaceous mudstone of mid-Cretaceous age.

The palynomorphs preserved in the carbonaceous mudstone containing the amber-bearing lignite indicate a mid-Cretaceous (~92–83 Ma) swampy temperate rainforest environment near the South Pole that was dominated by conifers. Such environmental conditions are ideally suited for the preservation and fossilization of wood and its associated plant resins because these require the presence of trees producing resin with a chemical composition suitable for fossilization as well as burial conditions devoid of oxygen .