A New Noncalcified Thallophytic Alga from the Lower Silurian of Anticosti Island, Eastern Canada

2014 ◽  
Vol 175 (3) ◽  
pp. 359-368 ◽  
Author(s):  
Yi Wang ◽  
Jisuo Jin ◽  
Renbin Zhan
Keyword(s):  
Eastern Canada ◽  
Lower Silurian ◽  
Anticosti Island

scholarly journals Early Silurian brachiopods (Rhynchonellata) from the Sælabonn Formation of the Ringerike district, Norway

2006 ◽  
Vol 53 ◽  
pp. 111-126
Author(s):  
Thomsen E. ◽  
Jin J. ◽  
Harper, D.A. T.
Keyword(s):  
Early Evolution ◽  
Eastern Canada ◽  
Additional Information ◽  
Lower Silurian ◽  
Anticosti Island

A revision of Kiær’s index fossils of "Etage" 6 in the Ringerike district of Norway reveals the presence of four species: Rostricellula wadti sp. nov., Platytrochalos ringerikensis sp. nov., Platytrochalos rabbei sp. nov., and Zygospiraella duboisi. Rostricellula is a common Ordovician rhynchonellide brachiopod and is known to occur in the Lower Silurian as a holdover taxon in only a few localities worldwide. Previously, Platytrochalos was known only from the Lower Silurian (Llandoverian) rocks of Anticosti Island, eastern Canada. The occurrence of this rare genus in the Ringerike district provides additional information for the early evolution and palaeogeography of the taxonomically enigmatic family Leptocoeliidae. Zygospiraella is regarded as an index genus for the Rhuddanian, and the presence of Z. duboisi provides a useful biostratigraphic control on the age of the Sælabonn Formation.

scholarly journals Late Ordovician jaw-bearing polychaetes from Anticosti Island, eastern Canada, and their biogeographic significance

2016 ◽  
Vol 53 (7) ◽  
pp. 731-738 ◽  
Author(s):  
Olle Hints ◽  
Petra Tonarová ◽  
André Desrochers
Keyword(s):  
Environmental Changes ◽  
Common Species ◽  
Upper Ordovician ◽  
Eastern Canada ◽  
Shallow Marine ◽  
Lower Silurian ◽  
Iapetus Ocean ◽  
The Family ◽  
Anticosti Island ◽  
First Time

The Upper Ordovician to lower Silurian shallow marine succession of Anticosti Island, eastern Canada, provides one of the most complete records across the Hirnantian in the world. This study reports a diverse assemblage of scolecodonts (polychaete jaws) from the upper Katian and Hirnantian Vauréal, Ellis Bay, and basal Becscie formations of western Anticosti. The collection of 10 samples includes ca. 30 species representing 10 families. The fauna is dominated by polychaetaspids, mochtyellids, paulinitids, and polychaeturids. The family Xanioprionidae and genera Pistoprion, Tetraprion, and Rakvereprion are documented for the first time from the Ordovician of Laurentia. The Anticosti polychaete fauna shows great similarity to the contemporaneous faunas of Baltoscandia. This is evidenced by a high relative abundance of mochtyellids and polychaeturids and a number of common species, thus suggesting that the closing Iapetus Ocean at that time did not constitute a barrier for the dispersal of jaw-bearing polychaetes. Some Laurentian influence is, however, indicated by the occurrence of hadoprionids. Distinct Katian Vauréal and Hirnantian Ellis Bay scolecodonts are likely reflecting faunal reorganization linked to local environmental changes rather than the initial phase of the Hirnantian mass extinction.

scholarly journals New rhenopyrgid edrioasteroids (Echinodermata) and their implications for taxonomy, functional morphology, and paleoecology

2019 ◽  
Vol 94 (1) ◽  
pp. 115-130
Author(s):  
Timothy A. M. Ewin ◽  
Markus Martin ◽  
Phillip Isotalo ◽  
Samuel Zamora
Keyword(s):  
Functional Morphology ◽  
Morphological Variability ◽  
Structural Diversity ◽  
Lower Paleozoic ◽  
Lower Silurian ◽  
Oral Plate ◽  
Single Compound ◽  
Oral Surface ◽  
Anticosti Island ◽  
High Degree

AbstractRhenopyrgids are rare, turreted edrioasterid edrioasteroids from the lower Paleozoic with a distinctive and apparently conservative morphology. However, new, well-preserved rhenopyrgid edrioasteroid material from Canada, along with a review of described taxa, has revealed broader structural diversity in the oral surface and enabled a re-evaluation of rhenopyrgid functional morphology and paleoecology.The floor plates in Rhenopyrgus viviani n. sp., R. coronaeformis Rievers, 1961 and, R. flos Klug et al., 2008 are well fused to each other and the interradial oral plate and lack obvious sutures, thereby forming a single compound interradial plate. This differs from other rhenopyrgids where sutures are more apparent. Such fused oral surface construction is only otherwise seen in some derived edrioblastoids and in the cyathocystids, suggesting homoplasy.Our analysis further suggests that the suboral constriction could contract but the flexible pyrgate zone could not. Thus, specimens apparently lacking a sub-oral constriction should not necessarily be placed in separate genera within the Rhenopyrgidae. It also supports rhenopyrgids as epifaunal mud-stickers with only the bulbous, textured, entire holdfasts (coriaceous sacs) anchored within the substrate rather than as burrow dwellers or encrusters.Rhenopyrgus viviani n. sp. is described from the Telychian (lower Silurian) Jupiter Formation of Anticosti Island, Québec, Canada and is differentiated by a high degree of morphological variability of pedunculate plates, broader oral plates, and narrower distal ambulacral zones. Specimens lacking or with obscured diagnostic plates from the Ordovician of Montagne Noire, France, and the Ordovician and Silurian of Girvan, Scotland are also described.UUID: http://zoobank.org/7f81d67f-4155-4719-8a45-b278ad70739d

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