Isoxys (Arthropoda) with preserved soft anatomy from the Sirius Passet Lagerstätte, lower Cambrian of North Greenland

摘要: Arthropods have a rich fossil record spanning the Phanerozoic. Biomineralized forms such as extinct trilobites are particularly common and proven index fossils for biostratigraphy. Forms with an unmineralized cuticle more rare, preserved only in so called konservat lagerstatten. Cambrian strata of Greenland yielded trilobite faunas potential intercontinental correlation strata, but also exceptionally fauna, Sirius Passet Lagerstatte. The first part this thesis is concerned biotratigraphy provisional Series 2 Greenland. second arthropods from Lagerstatte, 'Orsten' deposits Sweden. Perissopyge phenax occurs Henson Gletscher Paralleldal formations 3 boundary interval North It Sekwi Formation Yukon Territory, demonstrating that species may hold within Laurentia. An indeterminate shown to occur Ella Island North-East together Olenellus cf. hanseni, which similar truemani described Formation. If further corroborated it would offer tie-point t'Sron North-West Scotland yields Fritzolenellus lapworthi, herein reported time Bastion underlies Oelandocaris oelandica ‘Orsten’ series 4 Sweden early representative Crustacean stem lineage. Kiisortoqia avannaarsuensis new arthropod Lagerstatte robust antennulae strikingly 'raptorial' limb problematic anomalocaridids. ventral morphology 'bivalved' Isoxys volucris compared other assigned lagerstatten around world. Finally, Siriocaris trolla, similarities certain ‘trilobitomorphs’ seems lack important synapomorphies these taxa, though be due preservational limitations material at hand.