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-Tertiary (K-T) boundary is more severe in the marine than the terrestrial realm. We hypothesize that terrestrial ecosystems were able to recover faster than their marine counterparts. To test this hypothesis, we measured sedimentary delta C-13 as a tracer for global carbon cycle changes and compared it with palaeovegetational changes reconstructed from palynomorphs and cuticles across the K-T boundary at Sugarite, New Mexico, USA. Different patterns of perturbation and timescales of recovery of isotopic and palaeobotanical records indicate that the delta C-13 excursion reflects the longer recovery time of marine versus terrestrial ecosystems.