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RESEARCH PRODUCT

Palaeobiogeography of Austral echinoid faunas: a first quantitative approach

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description

Few studies have been devoted to the palaeobiogeography of Antarctic echinoids, all of them analysing and discussing distribution patterns in a qualitative way. The present work aims at exploring the evolution of palaeobiogeographic relationships of Austral echinoid faunas through four time intervals, from the Maastrichtian to the present day, using a quantitative approach: the Bootstrapped Spanning Network procedure. Analyses were successfully performed and improve our knowledge of biogeographic relationships between the different Austral regions. Biogeographic maps were produced that can be easily and intuitively discussed. Our results mostly agree with palaeobiogeographic studies performed on other benthic invertebrates and are congruent with the palaeogeographic evolution of Antarctica. However, two main points markedly contrast with other works: there is no evidence of an Austral provincialism at the end of the Cretaceous and early Cenozoic, and echinoid data suggest isolation of southern Argentina from other Austral regions, including Antarctica, in the Early Miocene.