Biogeography of Ordovician and Silurian gastropods, monoplacophorans and mimospirids
Jan Ove R. Ebbestad, Jiří Frýda, Peter J. Wagner, Radvan J. Horný, Mare Isakar, Sarah Stewart, Ian G. Percival, Verònica Bertero, David M. Rohr, John S. Peel, Robert B. Blodgett, Anette E. S. Högström, 2013. "Biogeography of Ordovician and Silurian gastropods, monoplacophorans and mimospirids", Early Palaeozoic Biogeography and Palaeogeography, D. A. T. Harper, T. Servais
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The biogeographical distribution of Ordovician and Silurian gastropods, monoplacophorans and mimospirids has been analysed on a generic level. The dataset contains 334 genera and 2769 species, yielding 1231 records of genera with 2274 occurrences worldwide. There is a bias towards eastern Laurentia, Baltica and Perunica records. Some 53.1% of the records are Ordovician. The study demonstrates that these molluscs are well suited to being used to improve understanding of Ordovician and Silurian biogeographical provinciality. Specific points are that: a Lower Ordovician assemblage is evident in Laurentia; the fauna of the Argentinean Precordillera is Laurentian until the Darriwilian, when taxa are shared with North China; Late Silurian gastropods from the Alexander terrane (SE Alaska) are unknown in Laurentia, but support a rift origin of this terrane from NE Siberia; Perunica, Ibero-Armorica and Morocco cluster together throughout the Ordovician but Perunica and Morocco are closer; Darriwilian–Sandbian deep-water Bohemian taxa occur in Baltica; a Laurentian–Baltica proximity is unsupported until the Silurian; Siberia clusters with North China and eastern Laurentia during the Tremadocian–Darriwilian; during the Gorstian–Pridoli Siberia clusters with the Farewell and Alexander terranes; North China may have been close to Laurentia and the Argentinean margin of Gondwana; and the affinity of Tarim taxa is problematic.