Original: Further analysis of oxygen and carbon isotopes from teeth of megafauna indicate the arid regional climates at the time of extinction were similar to arid regional climates of today, and that the megafauna were well adapted to arid climates.
Simplified: Further study of the teeth of megafauna shows the climate was dry at the time of extinction, similar to the dry climate of today, and that the megafauna were able to live in dry climates.