Argentine Antarctica observatory, where he also worked a post office was installed. Civil (employee of the Argentine company official post and telegraph) Hugo Alberto Acuna accounted hoist for the first time in an official way the flag of Argentina on the Argentine Antarctic sector, on 22 February 1904. Such an observatory became the Orcadas Base the oldest existing today across the Antarctic territory permanent human settlement. The Argentine corvette ARA Uruguay returned to Antarctica in 1905 (sailed from the port of Buenos Aires on 10 December 1904) to relieve staffing of the South Orkney and refer to Deception Island and Wiencke Island
Antarctica cooling of Antarctica occurred stepwise, as the continental spread changed the oceanic currents from longitudinal equator-to-pole temperature-equalising currents to latitudinal currents that preserved and accentuated latitude temperature differences. Africa separated from Antarctica in the Jurassic, around 160 Ma, followed by the Indian subcontinent in the early Cretaceous (about 125 Ma). By the end of the Cretaceous, about 66 Ma, Antarctica (then connected to Australia) still had a subtropical climate and flora, complete with a marsupial fauna. In the Eocene epoch, about 40 Ma Australia-New Guinea separated from Antarctica, so that latitudinal currents could isolate Antarctica from Australia, and the first