Phanerozoic flysch trace fossil diversity—observations based on an Ordovician flysch ichnofauna from the Aroostook–Matapedia Carbonate Belt of northern New Brunswick

Abstract

An Ordovician flysch trace fossil assemblage from the Aroostook–Matapedia Carbonate Belt, northern New Brunswick, consists of the following identifiable ichnogenera: Alcyonidiopsis, Asteriacites, Asterosoma, Belorhaphe, Bifasciculus, Buthotrephis, Chondrites, Cochlichnus, Cosmorhaphe, Diplichnites, Fucusopsis, Glockeria, Gyrochorte, Helminthoida, Helminthopsis, Neonereites, Paleodictyon, Planolites, Protopaleodictyon, Scalarituba, Spirodesmos, Spirorhaphe, and Taenidium. The stratigraphic range of six ichnogenera, viz. Glockeria, Gyrochorte, Helminthoida, Spirodesmos, Spirorhaphe, and Taenidium, is, therefore, now extended to rocks of Ordovician age.The diversity exhibited by the assemblage is inconsistent with currently proposed models of Phanerozoic flysch trace fossil diversity. It is suggested that existing models suffer from an inadequacy of sampling and systematic effort per period of geological time, as reflected by the limited number of post-Cambrian/pre-Cretaceous, particularly post-Carboniferous/pre-Cretaceous, adequately documented flysch ichnoassemblages. The assemblage described here clearly illustrates a significant radiation of deep-sea behavioural diversity in the Ordovician. This is possibly related to the development during the Ordovician of a sufficient oxygen concentration and supply of organic detritus in the deep sea or colonization of deeper-water habitats concomitant with the significant diversification of Ordovician shelf benthic communities.

Systematic ichnology of the Middle Ordovician Trenton Group, St Lawrence Lowland, eastern Canada

“…1, fig. 4) from the Cambrian of California and also resemble C. pudica described from Middle Ordovician to Middle Silurian strata of the United States, southern Jordan and Wales by, respectively, Osgood (1970), Seilacher (1970) and Pickerill (1977). Congeneric material has also been figured by Pickerill and Forbes (1979) Seilacher (1955), have frequently utilized the ichnogenus to describe morphologically similar but smaller scaled trilobite-produced traces (e.g.…”

“…17, H. hieroglyphica) to Oligocene (Ksiazkiewicz 1977) or even Recent (Dorjes 1978, Swinbanks andMurray 1981) age. It is a eurybathic form, though more frequently reported from deepwater flysch successions (Pickerill 1981) and is generally regarded as having been produced by polychaete and possibly priapulid annelids. Material -7 specimens.…”

“…If, indeed, the specimens are true Rhizocorallium, then they are conspecific with R. irregulare Mayer, 1954, as R. uliarense is a 3-dimensional spiral and R. jenense is shorter and typically oblique. Several attempts to photograph the specimens proved futile but a schematic figure is reproduced in Pickerill andForbes (1979, p. 2032, fig. 10).…”

“…Chamberlain 1977Chamberlain , 1978bChaplin 1980;Jordan 1981;Larson 1982) several authors have preferred to retain the forms as distinctive ichnogenera, particularly because poorer preserved material than that described by Chamberlain (1971) does not illustrate the morphological overlap and, instead, conforms more closely to individual ichnogenera as originally defined (e.g. Hantzschel 1975;Hakes 1976;Brasier and Hewitt 1979;Pickerill 1980Pickerill , 1981Marintsch and Finks 1982). We adopt the latter approach herein.…”

A Review of Proterozoic to Early Paleozoic Lithotectonic Terranes in New Brunswick, Canada and their Tectonic Evolution during Penobscot, Taconic, Salinic and Acadian Orogenesis

“…2, 5) were deposited adjacent to and on the Popelogan, Elmtree, and Miramichi terranes. Carbonates in the Matapédia Basin were likely sourced from the Laurentian platform (Malo 1988;Bourque et al 2000;Malo 2001 of the Pabos Formation (Katian) at the base; and gradationally overlying, rhythmically interlayered, thin-bedded, finegrained, argillaceous limestone and shale of the White Head Formation (Katian to lower Llandoverian) (Ayrton et al 1969;Pickerill 1980Pickerill , 1985Pickerill , 1987Pickerill , 1989Nowlan 1983c;Pickerill et al 1987;Bourque et al 2000;Malo 2001;Carroll 2003;.…”