RAPID BIOLOGICAL RECOVERY FOLLOWING THE CRETACEOUS-PALEOGENE BOUNDARY CATASTROPHE IN THE MAASTRICHTIAN TYPE AREA

Present-day marine biotas are increasingly subject to anthropogenically-forced extinctions. The study of the rapid global mass-extinction event at the Cretaceous-Paleogene (KPg) boundary can improve our understanding of the patterns of selective extinction and survival and the dynamics of ecosystem recovery. Outcrops in the Maastrichtian type area (SE Netherlands - NE Belgium border region) comprise an expanded KPg boundary succession, presenting a unique opportunity to study shallow marine ecosystem recovery within the first thousands of years following the Chicxulub impact event ∼66 Myr ago.

Here, the palynological, micro- and macropaleontological record of this unique succession is studied and reevaluated. Ecosystem changes across the K-Pg boundary in this region are rather limited, showing a general shift from epibenthic filter feeders to shallow-endobenthic deposit feeders. The fauna of the lowermost Paleocene still has many ‘Maastrichtian’ characteristics, a biological assemblage that survived the first hundreds to thousands of years into the earliest Paleocene. The shallow-marine oligotrophic carbonate sea of the Maastrichtian type area was inhabited by starvation-resistant, low nutrient-adapted taxa, that were seemingly less affected by the short-lived detrimental conditions of the K-Pg boundary catastrophe, such as darkness, cooling, food-starvation, ocean acidification, resulting in relatively high survival rates. The high survival rate allowed for a fast recolonization and rapid recovery of marine faunas in the Maastrichtian type area. While the recorded ecological shifts are consistent with a K-Pg collapse of primary productivity, the high survival rates and rapid recovery in the Maastrichtian type area compared to other sites highlight large regional variations in response to global catastrophes.