Fossil scarab and stag beetles—150 million years of evolution Scarab and stag beetles (Coleoptera: Scarabaeoidea) are particularly hard-shelled beetles. They appeared in the fossil record as early as the Jurassic Period and evolved into one of the largest beetle superfamilies with over 35,000 extant species. While some scarabaeoids are among the largest extant and fossil beetles, such as goliath and rhinoceros beetles, most of them are less than one centimeter long. Sufficiently detailed preservation of such small beetles requires either an extremely fine-grained sediment or embedment in natural resin. Our current research focuses on fossils from lagerstätten with particularly high-quality insect preservation, such as amber (Mesozoic and Eocene) and the oil shales of the Messel Formation (Eocene). Amber provides detailed three-dimensional preservation. In many of the Messel compression fossils, the original structural color is preserved. Both kinds of fossils provide a unique window into the past and help in reconstructing evolution and phylogeny of our study groups.