Am. Wood et al., The palaeozoogeography of Oligocene to Recent marine Ostracoda from the Neotropics (mid- and South America) and Antarctica, MAR MICROPA, 37(3-4), 1999, pp. 345-364
Classic biogeographical research has shown that the continent of South Amer
ica supports a diverse and priceless biota, of which ostracods are an impor
tant component. The distribution patterns of Oligocene to Recent shelf ostr
acods, from the Neotropics to Antarctica, are explained in terms of dispers
al and vicariant events. The quantitative examination of a newly constructe
d database, containing over 140 genera, has allowed the measurement of gene
ric similarity and endemicity between biotas of different geographical regi
ons. The measurement of these parameters has aided the construction of a se
ries of palaeoendemicity and communality maps. These maps emphasise changes
in the spatio-temporal distribution of mid to Late Tertiary ostracods, and
can aid in the recognition of abiotic mechanisms that modify genera distri
bution. It has been demonstrated that changes in the oceanic currents and w
ater-mass temperature are significant in the formation and maintenance of z
oogeographical domains in the Oligocene-Recent of the Neotropics and Antarc
tica. South America was an important centre of origin for ostracods during
the Oligocene, however, few genera appear able to disperse northwards towar
ds the Caribbean. The migratory success or failure of benthonic ostracods i
s closely linked to oceanographical and climatic conditions, and their phys
iology. Within the Meso-American region, filter and corridor pathways have
allowed rapid dispersal of shallow water ostracods which has lead to decrea
sed endemism. Although a distinctive ostracod assemblage was established in
the Oligocene of Antarctica, the expansion of the Drake Passage permitted
a new suite of cryophilic genera to emerge on the continent during the ?Mio
-Pliocene. Within the Meso-American region the alteration of oceanic circul
ation patterns, subsequent to the closure of the Panamanian portal, may hav
e initiated the development of a 'proto' Panamanian Province in the Early P
liocene. (C) 1999 Elsevier Science B.V. All rights reserved.