Article: Ediacaran biota of the Wernecke Mountains, Yukon, Canada
Guy M. Narbonne and Hans J. Hofmann
Soft-bodied metazoans, trace fossils, and metaphytes occur throughout several hundred metres of post-tillite, pre-Cambrian strata in the Wernecke Mountains, east-central Yukon Territory. The fossils occur in three unnamed units of siltstone deposited under shallow shelf and deeper water conditions. The oldest fossiliferous unit, the 'Goz siltstone', contains Charniodiscus? and Cyclomedusa sp. Siltstone unit 2 has yielded macrofossils (Beltanelliformis brunsae, Medusinites asteroides, Rugoconitesl sp.), trace fossils (Planolites montanus), and carbonaceous compressions (Vendotaenidl sp.). Siltstone unit 1, the youngest of the three siltstones, exhibits abundant soft-bodied macrofossils (Beltanella gilesi, Beltanelliformis brunsae, Charniodiscus cf. arboreus, Cyclomedusa plana, C. sp., Ediacaria flindersi, Kullingia? sp., Medusinites asteroides, Nadalina yukonenis gen. et sp. nov., Spriggia annulata, S. wadeae, Tirasiana sp.) and trace fossils (Gordia marina, Neonereitesl sp., Planolites montanus, and a backfilled burrow). Overlying Proterozoic carbonates contain only simple trace fossils.The Wernecke assemblage is similar to other occurrences of the Ediacaran fauna, but is most closely comparable with the Valday assemblage of the Russian Platform and the type assemblage in South Australia. Similarity of the faunal sequence in the Wernecke Mountains with that present in the type Ediacaran and Vendian implies that evolutionary stages previously identified within these systems may be globally significant.