Evolution of high-latitude molluscan faunas

• Main Author: Crame, J Alistair
• Format: Book Part
• Language: English
• Published: Oxford University PressOxford 1995
• Subjects: Arctic; Southern Ocean; Pacific; Fuller; Lowry; Dunbar; North Atlantic
• Online Access: http://dx.doi.org/10.1093/oso/9780198549802.003.0010; https://academic.oup.com/book/chapter-pdf/52430631/isbn-9780198549802-book-part-10.pdf

Abstract Two central, and interrelated, questions lie at the heart of investigations into the evolutionary history of polar and high- latitude marine biotas: how old are they?, and how isolated have they been through time? There is, perhaps, still a widespread impression that polar biotas are in some way less mature than their low-latitude counterparts. Because of repeated glaciations through the late Neogene and Quaternary, it is assumed generally that many taxa are still re-adjusting to life in high latitudes; by comparison, the more benign low- latitude regions are thought to be sites where life has proliferated comparatively undisturbed for long periods of time (see Dunbar, 1968 and references therein for a fuller development of this theme). Whereas there may have been open marine connections between the Arctic and North Atlantic oceans over at least the last 30 million years (=m.y.) (Marincovich et al., 1990), links between the Arctic and North Pacific oceans were severed from the Late Cretaceous to late Pliocene (65-3 m.y. ago). A common view of the Southern Ocean marine fauna is that it is the product of a considerable period of evolutionary isolation (e.g. Knox and Lowry, 1977; Lipps and Hickman, 1982).