Palaeoecology of a hypersaline Carboniferous ostracod fauna

Abstract. A high abundance, low diversity ostracod fauna has been collected from the Lower Carboniferous Dimock and Phillips limestones in Nova Scotia, Canada. The ostracod fauna consists of Paraparchites sp. aff. P. kellettae Sohn and Beyrichiopsis lophota Copeland, as well as rare specimens of Acratia acuta (Jones & Kirkby), Bythocypris aequalis (Jones & Kirkby), and Chamishaella suborbiculata (Munster).

Growth parameters for the dominant ostracod, Paraparchites sp. aff. P. kellettae, show that a multi-generation, progenetic, parthenogenetic population developed. This reproductive strategy caused rapid population growth and thereby allowed the species to take advantage of the available environmental resources.

When considered together, the ostracod fauna and the sedimentology indicate that physiologically stressful hypersaline conditions prevailed. The combined data therefore provide evidence for hypersalinity tolerance and heterochronous development amongst Carboniferous ostracods.