Rapid recovery of life at ground zero of the end-Cretaceous mass extinction

Abstract

The Cretaceous/Palaeogene mass extinction eradicated 76% of species on Earth. It was caused by the impact of an asteroid on the Yucatán carbonate platform in the southern Gulf of Mexico 66 million years ago , forming the Chicxulub impact crater. After the mass extinction, the recovery of the global marine ecosystem-measured as primary productivity-was geographically heterogeneous ; export production in the Gulf of Mexico and North Atlantic-western Tethys was slower than in most other regions, taking 300 thousand years (kyr) to return to levels similar to those of the Late Cretaceous period. Delayed recovery of marine productivity closer to the crater implies an impact-related environmental control, such as toxic metal poisoning , on recovery times. If no such geographic pattern exists, the best explanation for the observed heterogeneity is a combination of ecological factors-trophic interactions , species incumbency and competitive exclusion by opportunists -and 'chance'. The question of whether the post-impact recovery of marine productivity was delayed closer to the crater has a bearing on the predictability of future patterns of recovery in anthropogenically perturbed ecosystems. If there is a relationship between the distance from the impact and the recovery of marine productivity, we would expect recovery rates to be slowest in the crater itself. Here we present a record of foraminifera, calcareous nannoplankton, trace fossils and elemental abundance data from within the Chicxulub crater, dated to approximately the first 200 kyr of the Palaeocene. We show that life reappeared in the basin just years after the impact and a high-productivity ecosystem was established within 30 kyr, which indicates that proximity to the impact did not delay recovery and that there was therefore no impact-related environmental control on recovery. Ecological processes probably controlled the recovery of productivity after the Cretaceous/Palaeogene mass extinction and are therefore likely to be important for the response of the ocean ecosystem to other rapid extinction events.

Nature and timing of biotic recovery in Antarctic benthic marine ecosystems following the Cretaceous–Palaeogene mass extinction

“…Such a scenario implies that while nutrients were available for planktonic communities (Lowery et al . ), benthic communities and taxa may have been locally starved of food (D'Hondt ; Esmeray‐Senlet et al . ; Vellekoop et al .…”

“…; Tosolini ; Lowery et al . ), palaeoecology (e.g. motility, tiering, feeding strategy; Sheehan & Hansen ; Lockwood ), geographical range of a given species or clade (Jablonski & Raup ; Longrich et al .…”

Where the Ecological Gaps Remain, a Modelers' Perspective

“…Unfortunately, such efforts are sparse, particularly in the marine realm, as they often draw on paleontological time frames rather than simply observations from recorded history, as the degree of future environmental change may shift ecosystems into states that are governed by previously unobserved variables and interactions. Where available, fossil records have already given insights into the changing role of functional diversity, species composition and network structure with shifting pressures on ancient ecosystems and how a weakening of functional diversity exacerbated responses to later pressures (e.g., Yasuhara et al, 2008;Mitchell et al, 2012;Dunne et al, 2014;Roopnarine and Angielczyk, 2015;Pimiento et al, 2017;Lowery et al, 2018). Work on paleontological patterns of extinction underline that areas with high intrinsic risk of extinction (due the geographic range and taxonomic identity of species found there) coincide today with areas of rapid climate shifts and elevated human impacts (Finnegan et al, 2015;Pimiento et al, 2017).…”

Constructing a Timescale of Biotic Recovery across the Cretaceous–Paleogene Boundary, Corral Bluffs, Denver Basin, Colorado

“…However, a recent study of the diversity of benthic marine organisms within the Chicxulub Crater itself concluded that biologic productivity and diversity had recovered within 30 kyr, in contrast to sites in the other parts of the Gulf of Mexico that took 300 kyr or more to return to pre-impact levels (Lowery et al, 2018). Such heterogeneous patterns of K-Pg extinction and recovery have been documented for numerous other taxonomic groups and biogeographic regions suggesting this is more the rule than the exception (Jablonski, 1998;Håkansson and Thomsen, 1999;Kiessling and Baron-Szabo, 2004;Vajda and McLoughlin, 2007;Hull and Norris, 2011;Mizukami et al, 2013;Vajda and Bercovici, 2014;Witts et al, 2016;Donovan et al, 2018).…”

“…The detailed patterns of biotic recovery following the K-Pg mass extinction, however, are complicated and subject to regional biogeographic and taxonomic variability. For example, there is ongoing debate as to whether distance from the Chicxulub impact site can serve as proxy for the severity and timing of biotic recovery across the K-Pg boundary (Witts et al, 2016;Lowery et al, 2018). Consistent with this idea, are numerous studies of paleofloral assemblages suggesting that North America, which is relatively close to the Chixculub impact site, experienced higher rates of extinction, and delayed recovery, compared to southern hemisphere sites (Erwin, 2001;Nichols andFleming, 2002, Iglesias et al, 2007;Clyde et al, 2014).…”