Sirius Passet

Sirius Passet, a group of six fossil localities in Greenland’s Buen Formation, is one of the most important records of early animal life from about 518 million years ago. Discovered in 1984, it has been repeatedly studied since 1989, yielding perhaps 10,000 specimens. The fauna includes arthropods, sponges, and rarer groups, with especially important finds such as Halkieria, Kerygmachela, and Pambdelurion, which have shaped debates over the origins of modern animal phyla. Often compared with the Burgess Shale, Sirius Passet is probably older and closer in age to China’s Chengjiang fauna. Its exceptional preservation has also made it important for understanding ancient environments and fossilization processes.