proximity,contrary to a recent assertion (14).
We measured D/L ratios in eggshells of
both taxa from three regions (15): (i) an
extensive series (1200 analyses) from dune
and beach deposits within a 50-km radius of
Madigan Gulf (MG) in Lake Eyre, the terminal
playa of the Lake Eyre Basin; and modest
collections (ii) from a 50-km radius centered
on the north end of Lake Frome (LF) and (iii)
from a 150-km radius centered on the confluence
of the Darling and Murray rivers (DM)
(Fig. 1). The MG region is currently arid
[21°C, ;150 mm precipitation (16)]; LF is
semiarid (19°C, ;400 mm precipitation) and
has denser plant cover and thick riparian
vegetation; and the DM region is semiarid
(17°C, ;400 mm precipitation) with more
reliable stream flow.