Palaeontological evidence from both continental and marine deposits suggests that the Southern Hemisphere may have harboured biodiversity refugia in the wake of the bolide impact at Chicxulub, Mexico, 66.0 Myr ago (Ma)^1,2,3,4. The extinction rate of Southern Hemisphere nannoplankton was lower than that of their Northern Hemisphere counterparts, and their populations recovered nearly immediately². Nominally Mesozoic plant groups, including corystosperms and bennettitaleans, survived until at least the Palaeogene in Australia^1,5. Palynological data from New Zealand revealed a sudden but short-lived disturbance, with low overall extinction rates^6,7. In Patagonia, Argentina, palynomorphs from the latest Maastrichtian–early Danian Lefipán Formation exhibited low extinction, followed by the reappearances of Cretaceous pollen types³. Early Danian macrofloras from the Salamanca Formation in Patagonia are more diverse than comparable North American Palaeocene floras^8,9,10. A number of surviving lineages from other plant³ and vertebrate^11,12groups have also been identified, especially in Patagonia⁴, although marine invertebrate faunas in Antarctica underwent severe extinction¹³. K/Pg boundary sections in New Zealand have provided important insights into the response of terrestrial ecosystems^6,7,14,15,16, but until recently there has not been a series of well-dated, heavily sampled continental macrofloral localities anywhere in the Southern Hemisphere that spans both the terminal Cretaceous and earliest Palaeogene.

Plant–insect interactions are fundamental components of terrestrial food webs, and their sensitivity to major environmental perturbations is well known from deep time as well as the modern world^17,18,19,20. The diversity of insect-feeding damage on extant leaves in two tropical rainforests is positively correlated with the richness of insects that caused the damage, supporting the widespread use of insect damage on fossil leaves as a proxy for herbivorous insect diversity when suitable insect body fossils are absent²¹. In North Dakota, USA, insect-damage diversity on fossil leaves, especially specialized feeding such as mining and galling, declined considerably across the K/Pg boundary and remained low throughout WINA before increasing with the latest Palaeocene warming, approximately 9 Myr after the K/Pg boundary^17,18,20. The only exception to this pattern is the early Palaeocene (about 65 Ma) Mexican Hat locality in south-eastern Montana, USA, which has typical low-diversity flora but anomalously high insect damage diversity for the time; this pattern is attributed to a short-lived interval of decoupled plant and insect diversity following the K/Pg mass extinction^17,20.

Much less is known about the extinction and recovery of insect herbivores outside WINA. Late Palaeocene floras from Colombia are associated with low richness of plants and specialized insect-damage diversity as in Palaeocene WINA²², contrasting with high plant and insect-damage diversity on middle Palaeocene floras from France²³ and Spitsbergen²⁴. However, until now, no studies have investigated changes in insect-damage diversity based on terminal Cretaceous and early Palaeocene leaf floras from any non-WINA study area.

Full Text: http://www.nature.com/articles/s41559-016-0012

WFS,World Fossil Society,Riffin T Sajeev,Russel T sajeev