Data from: Plant taxonomic turnover and diversity across the Cretaceous-Paleogene boundary in northeastern Montana

The Cretaceous-Paleogene (K/Pg) mass extinction was a pivotal event in
Earth history, the latest among five mass extinctions that devastated
marine and terrestrial life. Whereas much research has focused on the
global demise of dominant vertebrate groups, relatively little is known
about local scale changes among plant communities across the K/Pg
boundary. This study investigates a suite of 11 floral assemblages
spanning the K/Pg boundary in northeastern Montana constrained within a
well-resolved chronostratigraphic framework. We evaluate the impact of the
K/Pg mass extinction on local plant communities as well as the timing of
recovery after the mass extinction. Our results indicate that taxonomic
richness dropped by ~28% from the Late Cretaceous to Paleocene, a moderate
decline compared with other records of plants across the K/Pg boundary. We
also find that plant taxonomic composition changed; 63% of latest
Cretaceous plant taxa disappeared across the K/Pg boundary, and although
conifers were more likely to survive the K/Pg event they declined in
abundance. Plant taxonomic richness returned to Late Cretaceous levels
within 900 kyr after the K/Pg boundary. Overall, plant communities
experienced major restructuring (changes in relative abundance) during the
K/Pg mass extinction, even though no major (e.g., family-level) plant
groups went extinct and local communities were quick to recover in terms
of taxonomic diversity. These results have direct bearing on our
understanding of vegetation change during diversity crises, the differing
responses of various plant taxonomic groups, and spatial variation in
extinction and recovery timing.