Sirius Passet
Sirius Passet is a Cambrian Lagerstätte in Greenland. The Sirius Passet Lagerstätte was named after the Sirius sledge patrol that operates in North Greenland. It comprises six places in Nansen Land, on the east shore of J.P. Koch Fjord in the far north of Greenland. It was discovered in 1984 by A. Higgins of the Geological Survey of Greenland. A preliminary account was published by Simon Conway Morris and others in 1987 and expeditions led by J. S. Peel and Conway Morris have returned to the site several times between 1989 and the present. A field collection of  perhaps 10,000 fossil specimens has been amassed. It is a part of the Buen Formation. Age. The fauna is inevitably compared to that of the Burgess Shale, although it is probably ten to fifteen million years older – vs. ) – and more closely contemporaneous with the fauna of the Maotianshan shales from Chengjiang, which are dated to . Preservation. The preservation of the Sirius Passet is not typical of a Burgess Shale type, but rather represents silicification associated with a death mask, recalling the 'Ediacara-type' preservation of the Precambrian Ediacara biota. Geochemical analysis indicates that the fossils lived close to the boundary  of an oxygen minimum zone, possibly being preserved in oxygen-starved periods. Fauna. Although the fauna has not yet been fully described, it is known to consist of a moderate number of arthropods and sponges, and rare representatives of other groups. It has yielded the problematic taxon "Halkieria", and the Panarthropods "Kerygmachela" and "Pambdelurion", all of which have played prominent roles in discussions about the origins of the modern animal phyla. Taxa from the Sirius Passet fauna. This is a partial list of taxa described from the Sirius Passet.