Llandovery (Early Silurian) orthide brachiopod associations from Anticosti Island, eastern CanadaThis article is one of a series 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.

Abstract

Five Llandovery orthide brachiopod associations, through cluster analysis, are delineated on Anticosti Island. The Levenea – Dicoelosia Association (A), occurring in the Goéland and Richardson members of the lower Jupiter Formation, represents a deep-water setting around or below the maximum storm wave base. The Flabellitesia – Dalejina Association (B), appearing in the Cybèle, Ferrum, and Pavillon members of the upper Jupiter Formation, indicates water depth in between the maximum and normal storm wave bases. The Isorthis ( Ovalella ) Association (C1), present in the Fox Point Member of Becscie Formation, corresponds to the shallower water setting around the normal storm wave base. The Mendacella bleikeriensis Association (C2), occurring in the Innommée, Sandtop, and Macgilvray members of Gun River Formation, characterizes the water depth slightly below the normal storm wave base. The Mendacella udauberis Association (D), appearing in the Merrimack Formation, signifies a water depth around the maximum storm wave base. The water depth indication of these associations may bear potential as future reference for other regions, but attention should be paid to the species level as some congeneric species can belong to different associations of different depth. The cluster analysis on orthide collections based on binary data demonstrates that statistical methods, Jaccard coefficient and Ward’s method of clustering, are practical and effective to delineate large brachiopod collections on Anticosti Island.