A Hirnantian (latest Ordovician) reefal bryozoan fauna from Anticosti Island, eastern Canada: taxonomy and chemostratigraphy

2009 ◽  
Vol 46 (3) ◽  
pp. 207-229 ◽  
Author(s):  
Andrej Ernst ◽  
Axel Munnecke
Keyword(s):  
Patch Reef ◽  
Stable Carbon Isotope ◽  
Late Ordovician ◽  
Stable Carbon ◽  
Eastern Canada ◽  
Generic Level ◽  
Rugose Corals ◽  
Stratigraphic Position ◽  
Yield Values ◽  
Anticosti Island

The Natiscotec outcrop on Anticosti Island, Canada (Ellis Bay Formation, Laframboise Member, Hirnantian, Late Ordovician), exposes a patch reef some 20–30 m in diameter, 2–3 m thick, with abundant rugose corals, as well as favositids and heliolitids. Reef capping and flanking sediments include typical Hirnantian brachiopods, such as Hirnantia , Hindella , and Eospirigerina . Within the reef peloidal microbialites encrusting bryozoan colonies are common. The bryozoan fauna includes three cystoporates, seven trepostomes, and three phylloporines. Two genera and two species are new: the cystoporate Natiscotecella tenuis n. gen. and n. sp. and the phylloporine Dilaminocladia natiscotecensis n. gen. and n. sp. Three more species are also new: the cystoporates Ceramopora clara n. sp. and Acanthoceramoporella spinigera n. sp. and the trepostome Revalotrypa honguedensis n. sp. Furthermore, we identify the three trepostomes Atactoporella aff. ortoni (Nicholson, 1874), Hallopora elegantula (Hall, 1852), and Monotrypella cf. aequalis Ulrich, 1882, and a phylloporine Parachasmatopora porkunensis Lavrentjeva, 1985. Four species are identified at generic level and in open nomenclature: the three trepostomes Lioclemella sp., Calloporella sp., and Trepostomata sp. and a phylloporine ? Ralfinella sp. The bryozoan fauna shows some affinities with the Late Ordovician fauna of Scandinavia. Stable carbon isotope investigations from brachiopod shells of the same outcrop yield values for δ13C of up to +6.7‰, which represent the highest values reported from the Anticosti succession so far. This indicates that the stratigraphic position of the outcrop is at or close to the peak of the globally recognized Hirnantian δ13C excursion.

A Late Ordovician age for the Whirlpool and Power Glen formations, New York

2016 ◽  
Vol 53 (7) ◽  
pp. 739-747 ◽  
Author(s):  
Laurenz Schröer ◽  
Thijs R.A. Vandenbroucke ◽  
Olle Hints ◽  
Thomas Steeman ◽  
Jacques Verniers ◽  
...  
Keyword(s):  
New York ◽  
Carbon Isotope ◽  
Stable Carbon Isotope ◽  
Late Ordovician ◽  
Stable Carbon ◽  
Fossil Assemblage ◽  
Isotope Data ◽  
Glomalean Fungi

A restudy of the palynology of the Whirlpool Formation and Power Glen Formation in New York (USA) yielded a diverse fossil assemblage with cryptospores, glomalean fungi, acritarchs, chitinozoans, scolecodonts, and small carbonaceous fossils. These new data, and particularly the presence of the chitinozoan index fossil Hercochitina crickmayi, combined with emerging stable carbon isotope data, suggest a Late Ordovician (Katian or Hirnantian) age for these formations, which is older than their previously suggested Silurian (Rhuddanian) age.

Environmental control on temporal and spatial differentiation of Early Silurian pentameride brachiopod communities, Anticosti Island, eastern CanadaThis article is one of a selection of papers published in this Special Issue on the theme The dynamic reef and shelly communities of the Paleozoic. This Special is in honour of our colleague and friend Paul Copper.

2008 ◽  
Vol 45 (2) ◽  
pp. 159-187 ◽  
Author(s):  
Jisuo Jin
Keyword(s):  
Water Depth ◽  
Environmental Control ◽  
Spatial Differentiation ◽  
Eastern Canada ◽  
Generic Level ◽  
Β Diversity ◽  
Brachiopod Fauna ◽  
Anticosti Island ◽  
High Degree ◽  
Depth Water

The Early Silurian carbonate succession of Anticosti Island, eastern Canada, contains a rich and diverse pentameride brachiopod fauna. Multivariate analyses of 91 samples (total 17 230 specimens) confirm a high degree of temporal segregation but only moderate spatial differentiation of the Virgiana , Pentamerus , Stricklandia , Ehlersella , Microcardinalia , and Clorinda communities. Most pentameride communities show a wider range of water depth than previously believed. The V. barrandei Community occupied a substrate setting from lower BA2 to upper BA3, whereas the V. mayvillensis Community lived mainly in BA4. The P. oblongus Community preferred a BA3 setting, comparable to the classic Pentamerus Community, but the P. palaformis Community was predominantly BA4. The stricklandiid communities have a high β diversity, dominated by various species of Stricklandia, Ehlersella, Microcardinalia, and Kulumbella, and occurred most commonly in BA4, but could extend to BA3 environments. The Clorinda Community of Anticosti Island preferred deep and quiet water settings, comparable to its widely accepted BA5 assignment elsewhere. At the generic level, the Virgiana, Pentamerus, and the stricklandiid communities have a largely overlapping BA range, but a clear stratigraphical separation. Thus, their temporal alternations were not likely controlled by water depth, water turbulence, or substrate conditions, but by fluctuating ocean water temperature, as suggested by chemostratigraphical and paleobiogeographical evidence.

Reefs during the multiple crises towards the Ordovician-Silurian boundary: Anticosti Island, eastern Canada, and worldwide

2001 ◽  
Vol 38 (2) ◽  
pp. 153-171 ◽  
Author(s):  
Paul Copper
Keyword(s):  
Patch Reef ◽  
Central Africa ◽  
Recovery Phase ◽  
Baltic Basin ◽  
Eastern Canada ◽  
Northeast Russia ◽  
Carbonate Production ◽  
Reef Recovery ◽  
Global Sea Level ◽  
Anticosti Island

Multiple latest Ordovician (Rawtheyan–Hirnantian) glaciations in central Africa, with concomitant global sea-level lowstands and cooler, restricted, equatorial carbonate shelves and ramps, interrupted by warmer interstadial highstands, had a dramatic global impact on the tropical shallow-water reef ecosystem and carbonate production. With the Ordovician-Silurian boundary strata on Anticosti Island as a global standard for a carbonate shelf-ramp setting, the latest Ordovician and earliest Silurian reveal three reef phases, ended by three extinctions. The first extinction, towards the end of the Rawtheyan, affected the last "Richmondian"-type reefs (Vaureal Formation, Mill Bay Member). The second extinction was less pronounced, ending with reefs at the base of the Prinsta Member (Ellis Bay Formation), interpreted as the top of the Normalograptus extraordinarius graptolite Subzone. The third and most severe extinction phase capped the Laframboise patch reef complex (Ellis Bay Formation), at the top of the Normalograptus persculptus Zone. In the paleotropics, the Hirnantian interglacials showed higher biodiversity than either the preceding Rawtheyan or following Rhuddanian (early Llandovery) warm intervals, a feature perhaps achieved by high innovation rates via introduction of "Silurian" reef biotas during the Hirnantian. The Anticosti reef succession is compared with latest Ordovician reefs from northwestern Europe (Baltic Basin and U.K.), the northwestern margins of Gondwana (Spain and Austria), the Urals, Siberia, Kazakhstan, northeast Russia, and China. Reefs show a global decline from the late Caradoc through late Ashgill, marked by hiatuses towards the O–S boundary. A protracted 3–4 million-year recovery phase for Early Silurian tropical marine biotas, generally without reefs, marked the succeeding Rhuddanian; full reef recovery was delayed until the mid-Aeronian.

Five new genera of Late Ordovician-Early Silurian brachiopods from Anticosti Island, eastern Canada

1995 ◽  
Vol 69 (5) ◽  
pp. 846-862 ◽  
Author(s):  
Paul Copper
Keyword(s):  
New Taxa ◽  
Mass Extinction ◽  
Type Species ◽  
Late Ordovician ◽  
Present Knowledge ◽  
Early Evolution ◽  
New Genera ◽  
Eastern Canada ◽  
Anticosti Island ◽  
First Time

Uninterrupted, ~800 m thick, Ashgill through Llandovery carbonate strata from Anticosti Island (eastern Canada) reveal five new brachiopod genera, enhancing present knowledge about the early evolution of the spire-bearing order Atrypida, spanning some 10.2 million years of time, and a global mass extinction crisis. New taxa include smooth-shelled forms such as the Late Ordovician genus Xysila, type X. astaca n. sp., and two new Early Silurian genera, Becscia, type B. scissura n. sp., and Cerasina, type C. pycnata n. sp. New costate genera include the Early Silurian reef-dwelling form Dihelictera, type D. acrolopha n. sp., and a deeper water inhabitant, Joviatrypa, type J. brabyla n. sp. For comparison with these new taxa, the spiralia and jugal processes of the type species of the Llandovery genera Protatrypa and Meifodia are illustrated and described for the first time.

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