Abstract:
The Quaternary period of the geographic history of earth includes two geologic epochs viz., the
Pleistocene and the Holocene. Both epochs divided the faunal stages and human cultural phases
based on climate and sea level changes that took place during these periods. The Quaternary ice
age began roughly about 2.58 MYO with cool and dry climate conditions. The extinct
Australopithecines and many other extinct genera of mammalian mega fauna appeared during
this time. Thus, the Quaternary period shows the extinctions of numerous predominantly larger,
especially mammalian mega faunal species, many of them lived during the transition from the
Pleistocene to the Holocene epoch. The debate on the demise of the mammalian megafauna is
often characterized by two highly polarized points of view: (1) climate-induced extinction; and
(2) human-induced extinction. In Pleistocene period most parts of the Northern Hemisphere of
earth were covered with glaciers creating a cold climate. Due to this glacial formation the main
sea level was much lower than it is today. The low sea level facilitated the connection of Sri
Lanka with the Indian mainland with a land bridge. Therefore, a number of mega fauna and
micro fauna were able to cross to Sri Lanka from India along this land bridge. The last land
bridge was emerged around 7500 years BP. During the Pleistocene era Sri Lanka experienced
heavy rainfall causing the emergence of rain forest in the country. The heavy rainfall in the
Sabaragamu Basin also provided habitats for a number of marsh loving animals including
mammals. However, at the end of the Pleistocene epoch, drastic climatic changes were occurred
resulting in the extinction of a number of animal taxa. Pleistocene fauna in Sri Lanka is known
as Rathnapura Fauna. Their fossils are found in alluvial deposits in the Sabaragamu basins.
