Understanding how seasonal temperatures on land respond to global greenhouse climate conditions is important for
predicting effects of climate change on ecosystem structure, agriculture and distributions of natural resources. Fossil floral
and faunal assemblages suggest winter temperatures in middle and high latitude continental interiors during the Cretaceous
and early Cenozoic were at or above freezing, whereas terrestrial summer temperature estimates are uncertain.
Carbonate clumped isotope (Δ_(47)) temperature estimates from lacustrine and paleosol carbonates appear to be generally
biased toward summer temperatures in middle and high latitudes. Though problematic for reconstructing mean annual
temperature (MAT), this bias presents an opportunity to reconstruct terrestrial summer temperatures and, through
comparison with paleobotanical data, estimate past terrestrial seasonality
