New occurrences of Oldhamia and other trace fossils in the Cambrian of the Yukon and Ellesmere Island, arctic Canada

Abstract

Trace fossil assemblages from green and maroon argillites at 34 localities in the British Mountains and Barn Mountains of northernmost Yukon, and 3 localities in the Grant Land Formation of northern Ellesmere Island contain abundant Planolites spp., Oldhamia curvata, Oldhamia flabellata, and Oldhamia radiata, and rare Oldhamia antiqua, Oldhamia? wattsi (n.comb.), Bergaueria hemispherica, Cochlichnus sp., Didymaulichnus? sp., Helminthoidichnites sp., Monomorphichnus sp., Protopaleodictyon sp., and Tuberculichnus? sp. Additionally, 11 new sites in the Selwyn Mountains of north-central Yukon have yielded an ichnofauna including Helminthorhaphe sp., O. curvata, O. flabellata, O. radiata, Plagiogmus? sp., Planolites spp., and unidentified small hemispherical traces. All these assemblages are interpreted as Early Cambrian to early Middle Cambrian, based on comparison with Oldhamia-bearing ichnofaunas of similar age in North America, Argentina, and western Europe, and on archaeocyathids and olenellids in overlying units.

Detrital zircon geochronology of quartzose metasedimentary rocks from parautochthonous North America, east-central Alaska

“…13 Dusel-Bacon et al (1995). is Early Cambrian to early-Middle Cambrian in age (Hofmann et al, 1994;MacNaughton et al, 2016). The Oldhamia-bearing rocks in the northwestern Circle quadrangle were correlated by Weber et al (1992) with the Wickersham grit unit mapped in the Livengood quadrangle to the west, whereas the two occurrences of Oldhamia north of the northern strand of the Tintina fault are included in the Crazy Mountains terrane of Churkin et al (1982) (Fig.…”

Trace fossils from the Permian Teresina Formation at Cerro Caveiras (S Brazil)

“…Lindholm & Casey, 1990;Hofmann et al, 1994;Buatois & Mángano, 2003;Seilacher et al, 2005;Seilacher, 2007). While most occurrences of Oldhamia are associated with Cambrian deposits, changes of the behavior program developed by its producers have emerged throughout the Paleozoic, probably in response to changes in feeding strategy, as noted in Ordovician, Carboniferous and Permian records (Seilacher, 2003(Seilacher, , 2007Seilacher et al, 2005;MacNaughton, 2007).…”

An early Cambrian shallow-marine ichnofauna from the Puncoviscana Formation of northwest Argentina: the interplay between sophisticated feeding behaviors, matgrounds and sea-level changes

“…Discussion.-Helminthoidichnites tenuis is one of the most common components of Ediacaran and lower Cambrian ichnofaunas (e.g., Hofmann et al, 1994;MacNaughton et al, 2000;Jensen et al, 2006). This ichnotaxon is interpreted as a grazing trace (pascichnion) most likely produced by vermiform animals (Buatois et al, 1998).…”

“…Oldhamia is essentially a Cambrian ichnogenus, being particularly abundant during the early to middle Cambrian (Lindholm and Casey, 1990;Herbosch and Verniers, 2011). Although it is more common in deep-marine environments (e.g., Hofmann et al, 1994), it also occurs in shallow-marine deposits (e.g., Goldring and Jensen, 1996) (see Paleoenvironmental significance of Oldhamia).…”