Depth related brachiopod faunas from the lower Cambrian Forteau Formation of southern Labrador and western Newfoundland, Canada

A diverse fauna of organophosphatic brachiopods is described from the late early Cambrian (Series 2, Stage 3-4) Forteau Formation of southern Labrador and western Newfoundland. The total fauna includes 11 species representing a wide selection of Cambrian brachiopod groups. Three distinct assemblages are recognized: Assemblages 1 and 2 are found in shallow water carbonates in association with archaeocyathans in southern Labrador and the western side of the Great Northern Peninsula of western Newfoundland. Assemblage 3 is found in a distal shelf setting of Gros Morne National Park. Assemblages 1 and 2 are found in stratigraphic continuity and define two brachiopod biozones, a lower Hadrotreta taconica zone and a higher Paterina zone, respectively. The presence of H. taconica in brachiopod Assemblage 3 possibly indicates time equivalence of Assemblage 1 but in a deep water setting. The identification of distinct time equivalent brachiopod Assemblages (1 and 3) in shallow and deep water environments of the Forteau Formation allow for the first time an analysis of environmental constraints determining the distribution of individual brachiopod taxa in the lower Cambrian succession of eastern Laurentia. Comparison to faunas from other areas indicates that the identified distributional patterns can be extended to other brachiopod faunas found along the Cambrian palaeocoast/margin of eastern Laurentia. The study indicates that specific brachiopod taxa can be used as indicators of palaeodepth; Botsfordia caelata in shallow environments and Eoobolus priscus and Eothele tubulus in deeper water. The following new taxa are described: Kyrshabaktella diabola n. sp., Pustulobolus triangulus n. gen et n. sp., Acrothyra bonnia n. sp. C.B. Skovsted. Swedish Museum of Natural History, Department of Palaeobiology, SE-104 05 Stockholm, Sweden (corresponding author). [email protected] I. Knight. Government of Newfoundland and Labrador, Department of Natural Resources, Geological Survey, P.O. Box 8700, St. John’s, Newfoundland and Labrador, A1B 4J6. [email protected] U. Balthasar. School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, http://zoobank.org/482B4F4C-E674-46BB-B4E7-2768C8E0D357 Skovsted, C.B., Knight, I., Balthasar, U., and Boyce, W.D. 2017. Depth related brachiopod faunas from the lower Cambrian Forteau Formation of southern Labrador and western Newfoundland, Canada. Palaeontologia Electronica 20.3.54A: 1-52. https://doi.org/