More than 85 percent of Australian terrestrial genera with a body mass exceeding
44 kilograms became extinct in the Late Pleistocene. Although most
were marsupials, the list includes the large, flightless mihirung Genyornis newtoni.
More than 700 dates on Genyornis eggshells from three different climate
regions document the continuous presence of Genyornis from more than
100,000 years ago until their sudden disappearance 50,000 years ago, about the
same time that humans arrived in Australia. Simultaneous extinction of Genyornis
at all sites during an interval of modest climate change implies thatThe fossil record shows that E. longirostris has
apparently undergone no evolutionary change in
skeletal morphology over the last 400,000 yr, which
may be one of the best-documented instances of
prolonged evolutionary stasis in a small reptile on an
oceanic island. Unfortunately, we still do not know
whether the differences it exhibits from other species
of Eumeces are the result of adaptation to the insular
environment of Bermuda or whether the Bermuda
skink is an unchanged relict of an ancestral species
that has since become extinct on the mainland.
human impact, not climate, was responsible.