Geological Museum, Natural History Museum of Denmark, University of Copenhagen
Ordovician palaeogeography and palaeoclimate pages:17-17
Absolutely final meeting of IGCP 503: Ordovician palaeogeography and palaeoclimate location:Copenhagen, Denmark date:31 August - 4 September 2009
Terms such as terrane, micro-continent, and micro-plate are commonly used in geodynamical models by structural geologists and tectonicians. On the other hand, terms such as realm, province, and biochors are used by palaeontologists and palaeobiogeographers to describe the geographical distribution of living or fossil organisms.
In recent decades, it has become fashionable to create new terranes or microcontinents or new provinces. Selected palaeontological or palaeomagnetic data, not necessarily placed in a general context, have led to the creation of numerous new palaeogeographical units around the world. Moreover, there is often a conceptual confusion between palaeogeographical units (physical entities) and biogeographical units (biotic entities) that has resulted in a circular reasoning when one wishes to use biogeographical data to test palaeogeographical reconstructions based on geological and palaeomagnetic data.
For the Early Palaeozoic periods the palaeogeographical and palaeobiogeographical terminology has often been used indiscriminately and inconsistently in publications concerning palaeogeographical reconstructions, plate tectonic configurations, and palaeobiogeographical distributions. The confusion of terms has led to a mixing of terminology and palaeogeographical concepts. This is particularly valid for the peri-Gondwanan margin during the Early Palaeozoic and the discussion between palaeobiogeographers and palaeogeographers, where terms such as terranes and provinces, for example, have been confused.
In the present paper, we discuss the different palaeobiogeographical concepts in the Early Palaeozoic, by comparing different models and reconstructions, with the major aim of clarifying the conceptual differences in terminology used by palaeobiogeographers and palaeogeographers.
We advocate the use of distinct and consistent terminologies for both palaeogeographic and palaeobiogeographic units, following the guidelines of the group ‘Friends of Paleobiogeography’ with a coherent palaeobiogeographic classification and nomenclature of palaeobiogeographic units (biochoremas) as proposed by Westermann (2000) and Cecca and Westermann (2003).