The remains of "Therizinosaurus" were found in the well-known Nemegt Formation in the Gobi Desert, dating back to the Maastrichtian stage about 70 million and 68 million years ago. The environments that "Therizinosaurus" inhabited have been determined by the δ13C level preserved on the tooth enamel of many herbivorous dinosaurs and the numerous petrified wood across the formation, and consisted of large meandering and braided rivers with extensive woodlands composed of large, enclosed, canopy-like forests of Araucarias that supported diverse herbivorous dinosaurs like "Therizinosaurus". The climate of the formation was relatively temperate (mean annual temperatures between 7.6-8.7 °C), characterized by monsoons with cold, dry winters and hot, rainy summers with the addition of mean annual precipitations between 775 mmm and 835 mmm, a precipitation that was subject to prominent seasonal fluctuations. The wet environments of the Nemegt Formation may have acted as an oasis-like area that attracted oviraptorids from arid neighbour localities such as the Barun Goyot Formation, as evidenced on the presence of "Nemegtomaia" in both regions.