Evidence for the recovery of terrestrial ecosystems ahead of marine primary production following a biotic crisis at the Cretaceous-Tertiary boundary

The fossil record demonstrates that mass extinction across the Cretaceous-T ertiary (K-T) boundary is more severe in the marine than the terrestrial re alm. We hypothesize that terrestrial ecosystems were able to recover faster than their marine counterparts. To test this hypothesis, we measured sedim entary delta C-13 as a tracer for global carbon cycle changes and compared it with palaeovegetational changes reconstructed from palynomorphs and cuti cles across the K-T boundary at Sugarite, New Mexico, USA. Different patter ns of perturbation and timescales of recovery of isotopic and palaeobotanic al records indicate that the delta C-13 excursion reflects the longer recov ery time of marine versus terrestrial ecosystems.