Preface to 'Evolution, Extinction and Biogeography in Gondwana'
Robert S. Hill
Australian Journal of Botany 49(3) I - ii
Abstract
The macrofossil record of the plant family Cunoniaceae in Australia is
summarised and reviewed where necessary by using detailed studies of the
morphology of extant genera. Eleven of the 26 Cunoniaceae genera are
represented in the Australian macrofossil record and include leaves and leaf
fragments, foliar cuticle and reproductive structures, and range from Late
Paleocene to Quaternary in age. Macrofossils show that some genera had a
different or more widespread distribution in Australia during the Cenozoic,
with two genera (Weinmannia and
Codia) having become extinct from the continent. Changes
in climate, including increasing cold, frost, dryness, seasonality, or some
combination of these, or a reduction in vegetation disturbance regimes (e.g.
volcanism, uplifting, landslips), may be implicated in the regional or
continental extinctions demonstrated by the macrofossil record. Many extant
genera (Schizomeria, Vesselowskya,
Callicoma, Ceratopetalum,
Acsmithia, Codia) had evolved by
the Early Oligocene or earlier (Eucryphia, Late
Paleocene; Ceratopetalum, Middle Eocene), perhaps with
generic diversification more or less complete by the end of the Early Cenozoic
or earlier. A Cretaceous origin of the family is possible, and may account for
its widespread distribution on Southern Hemisphere landmasses, although
long-distance dispersal events are required to explain some modern geographic
disjunctions.
Full text doi:10.1071/BTv49n3_PR
© CSIRO 2001





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