Hoh Xil Basin is crucial for studying Tibetan paleoclimate and paleoelevation.
Age of sedimentary Yaxicuo Group at Hoh Xil Basin still remains under debate.
Late Eocene is inferred based on palynological morphologies and assemblages.
Hoh Xil Basin was dry and no higher than 2000 m a.s.l. during the Late Eocene.