The Cenozoic diversity of Antarctic Bivalves does not reflect Southern Ocean environmental changes after the Antarctic thermal isolation

• Main Authors: Quaglio, Fernanda, Anelli, Luiz Eduardo, dos Santos, Paulo Roberto, Warren, Lucas Veríssimo
• Format: Article in Journal/Newspaper
• Language: Portuguese
• Published: Associação Brasileira de Ciência Ecológica e Conservação 2017
• Subjects: Antarctica; Southern Ocean; bivalves; diversity; paleoecology; Cenozoic; Antártica; Oceano Austral; diversidade; paleoecologia; Cenozóico; Antarctic; Austral; The Antarctic; Antarc*
• Online Access: https://revistas.ufrj.br/index.php/oa/article/view/8057

Environmental changes occurred in Southern Hemisphere in response to the separation of Antarctica from Australia, around Eocene/Oligocene boundary, and from South America, during the late Oligocene, greatly affected biodiversity in Southern Ocean. Although it is generally accepted that the Antarctic thermal isolation affected the Cenozoic biodiversity by changing environmental conditions, there is no available study concerning the Cenozoic dynamics of Antarctic bivalve diversity in relation to climatic changes. In this study, an assembling of all available bivalve family and genera described from Antarctic Cenozoic deposits as well as modern bivalve family and genera were analyzed in order to evaluate possible effects of Cenozoic environmental changes on Antarctic bivalve diversity along the Cenozoic. The main conclusion of this work is that the currently known Cenozoic record of the Antarctic bivalves does not reflect Cenozoic environmental changes. This is probably related to the restricted record of Antarctic bivalves, and therefore to the scarce knowledge on the Cenozoic diversity of the group. The analysis also revealed that Cenozoic intervals of highest diversity are attributed to few areas in Antarctica that are available for paleontological exploration. Besides, the large number of recorded bivalve taxa in some Cenozoic intervals may be related to the stratigraphic control of deposits. As mudanças ambientais ocorridas no Hemisfério Sul em resposta à separação da Antártica e a Austrália, no limite Eoceno/Oligoceno, e da Antártica e a América do Sul, durante o final do Oligoceno, afetaram profundamente a biodiversidade das regiões do Oceano Austral. Muito embora seja amplamente aceito que o isolamento térmico da Antártica influenciou a biodiversidade ao alterar as condições ambientais da região, não há estudos relacionados à dinâmica de diversidade dos bivalves antárticos frente às mudanças climáticas ao longo do Cenozóico. No presente estudo, foi analisado o números de famílias e gêneros de bivalves ...