Conodont biostratigraphy of the Codroy Group (Lower Carboniferous), southwestern Newfoundland, Canada

Abstract

Four stratigraphically successive conodont assemblage zones have been recognized in the Lower Carboniferous Codroy Group of southwestern Newfoundland. The Diplognathodus Zone is confined to the basal Ship Cove Limestone, and to a highly fossiliferous correlative at Aguathuna. The overlying Taphrognathus Zone occurs in carbonates in the stratigraphic interval above the sequence of massive sulphates and thick clastics. The Taphrognathus Zone, as well as the successive Cavusgnathus Zone, has been recognized on Fischells Brook, as well as in the complex section south of Codroy. The highest conodont zone, the Gnathodus Zone, has been recognized in the Crabbes–Jeffreys Limestone of the St. George's Bay area, and from south of Codroy.The discovery of conodonts of the Diplognathodus Zone in marine strata that are stratigraphie and lithologie correlatives of the Macumber and the Gays River Formations of Nova Scotia now makes it possible to microfaunally characterize the A Subzone, a macrofaunal subzone established in the Windsor Group of Nova Scotia.The Taphrognathus and Cavusgnathus Zones of the Codroy Group of Newfoundland correlate with the lower and upper B Subzone of the Lower Windsor Group of Nova Scotia, respectively. The Gnathodus Zone correlates with the C, D, and E Subzones of the Upper Windsor Group of Nova Scotia.

Comments on: Testing hypotheses of element loss and instability in the apparatus composition of complex conodonts (Zhang et al.)

“…(). The P 2 element of Hindeodus has previously been demonstrated to be an angulate element in the middle to late Mississippian H. cristulus (Sweet ; Horowitz & Rexroad ; von Bitter & Plint‐Geberl ); in the late Mississippian to early Permian H. minutus (von Bitter ; Baesemann ; Merrill ; Horowitz & Rexroad ; Rasmussen & Håkansson ); in the middle Permian H. excavatus (Sweet ; Wardlaw & Collinson, ; Wardlaw ); in the late Permian H. julfensis (Sweet ; Nestell & Wardlaw ; Metcalfe ) and H. latidentatus (Wardlaw et al . ); and it has even previously been recognized in H. parvus from the Early Triassic (Kozur ).…”

Discovery of aMississippian–earlyBashkirian carbonate platform coeval with condensed cephalopod limestone sedimentation inNW Spain

“…Furthermore, the oldest European occurrence of Diplognathodus sp. is notable (Figure n), because it is only known in Viséan beds of the Codroy Group in the Maritime Provinces of Canada (von Bitter & Plint‐Geberl, ). All these taxa are considered shallow‐water dwellers according to Sandberg and Gutschick () but occur together with deeper water taxa, such as Gnathodus and Vogelgnathus (Table ).…”

Palynostratigraphy and lithostratigraphy of Carboniferous Upper Codroy Group and Barachois Group, southwestern Newfoundland

“…In the partially marine Upper Codroy Group, there is considerable biostratigraphic control from a diverse macrofauna of brachiopods, corals, trilobites, and molluscs (Bell 1948), and a microfauna of foraminifera (Mamet 1970) and cono- donts (von Bitter and Plint-Geberl 1982), thus enabling correlations to be made with the Upper Windsor Group of Nova Scotia (von Bitter et al 2007). …”