Cambro‐Ordovician trace fossils from the SW‐Norwegian Caledonides

Abstract

A diverse trace fossil association is described for the first time from low-grade metamorphic rocks of the SW-Norwegian Caledonides. The investigated cliff sections with autochthonous to parautochthonous metasediments comprise a coarsening-and thickening-upward succession interpreted as prograding delta deposits. Sedimentary features indicate a tide-influenced environment. Twenty-one ichnospecies have been identified and assigned to the Cruziana and Skolithos ichnofacies, including the oldest record of Beaconites capronus and Macaronichnus segregatis. Cruziana ichnostratigraphy (sensu lato), previously rarely used in other palaeocontinents than Gondwana, allows an age determination for these metasediments of Middle Cambrian to Lower Ordovician as indicated by the presence of Cruziana barbata, C. furcifera, C. rugosa, C. semiplicata, Didymaulichnus rouaulti and Rusophycus ramellensis. Baltica was geographically the most isolated from the other three large continents (Gondwana, Laurentia and Siberia) during Cambro-Ordovician time, and provinciality of faunal assemblages (e.g. brachiopods, conodonts) has been proved and is also supposed for trilobites by some authors. However, although the Cruziana ichnospecies result from a high specialization of their tracemakers, and therefore only a small group of trilobite species is eligible for its origin, the ichnospecies reported from Baltica occur also on other palaeocontinents and do not support the assumption of trilobite provincialism.

Archetypally Siluro-Devonian ichnofauna in the Cowie Formation, Scotland: implications for the myriapod fossil record and Highland Boundary Fault Movement

“…Meniscate burrows reported from the mid-Silurian Grampians Group of Western Australia probably formed in a fully marine setting (George, 1994;contra Gouramanis et al, 2003). Elsewhere (2000), Gand et al (1997), Germs (1972), Goldring and Pollard (1995), Graham and Pollard (1982), Hakes (1976), Han and Pickerill (1994), Häntzschel (1975), Hunter and Lomas (2003), Knaust (2004), Kulkarni and Borkar (2014), Kumpulainen et al (2006), Maples and Archer (1987), Maples and Suttner (1990), Martino (1989), Mikulas (1993), Minter et al (2007), Morrissey and Braddy (2004), Narbonne (1984), O'Sullivan et al (1986), Pearson (1992), Pickerill (1991), Pickerill (1992), Pickerill et al (1987), Pickerill et al (1984), Prescott et al (2014), Qi et al (2012), Savoy (1992), Smith (1993), Stephenson and Gould (1995), Tanoli and Pickerill (1989), Thomas and Smith (1998), Tunbridge (1984) and Weber and Braddy (2004). they are reported in Late Silurian-Early Devonian deposits from transitional continental-marine settings in the Ringerike Group of Norway, Tumblagooda Sandstone of Western Australia, and Mereenie Sandstone of the Northern Territory, Australia (Trewin and McNamara, 1994;Davies et al, 2006 Gouramanis and…”

Cruziana semiplicata from the Furongian (Late Cambrian) of Severnaya Zemlya Archipelago, Arctic Russia, with a review of the spatial and temporal distribution of this ichnospecies

“…There is no evidence for outer lobes or marginal ridges in this material. Knaust (2004) reported C. semiplicata from the southern Norwegian Caledonides, but with a Furongian age based on trace fossils. Finally, Miroshnikov and Kravtsov (1960, figure 11) figured Cruziana from the Furongian Chopko Formation of the Norilsk area, northern Siberia that appears similar to the narrow form of the October Revolution Island C. semiplicata, though unfortunately no scale was provided.…”

“…However, there are exceptionally few reports of Cruziana from the Tremadocian of Baltica. Knaust (2004) reported on Lower Ordovician Cruziana from the Caledonides of south-west Norway, but without independent age constraints. More data on trace fossils from Digermul Peninsula, northern Norway, would be of great interest as these areas are reported to contain rich and well-preserved material of Cruziana in a well-constrained Cambro-Ordovician succession (cf.…”

Lower Ordovician (Arenig) shallow-marine trace fossils of the Pochico Formation, southern Spain: palaeoenvironmental and palaeogeographic implications at the Gondwanan and peri-Gondwanan realm

“…Remarks: This trace fossil was assigned to Didymaulichnus Young, 1972(e.g., Crimes, 1970Knaust, 2004), which mostly smooth, bilobate ridge. However, many authors ascribed it to Cruziana ďOrbigny (e.g., Neto de Carvalho, 2006;Seilacher, 2007).…”

“…Nevertheless, the palaeogeographical restriction is not strict. The C. rugosa group and other trace fossils, e.g., Trichophycus venosus, were reported from the Norwegian part of Baltica (Knaust, 2004) despite the fact that Baltica during the Ordovician was separated from Gondwana by the Tornquist Sea (e.g., Cocks and Torsvik, 2002).…”