Fossil evidence reveals how plants responded to cooling during the Cretaceous-Paleogene transition

Author(s)
Yi-Ming Cui, Wei Wang, David-Kay Ferguson, Jian Yang, Yu-Fei Wang
Abstract

BACKGROUND: Around the Cretaceous-Paleogene (K-Pg) boundary, an obvious global cooling occurred, which resulted in dramatic changes in terrestrial ecosystems and the evolutionary trends of numerous organisms. However, how plant lineages responded to the cooling has remained unknown until now. Between ca. 70-60 Ma Mesocyparis McIver & Basinger (Cupressaceae), an extinct conifer genus, was distributed from eastern Asia to western North America and provides an excellent opportunity to solve this riddle. RESULTS: Here we report a new species, Mesocyparis sinica from the early Paleocene of Jiayin, Heilongjiang, northeastern China. By integrating lines of evidence from phylogeny and comparative morphology of Mesocyparis, we found that during ca.70-60 Ma, the size of seed cone of Mesocyparis more than doubled, probably driven by the cooling during the K-Pg transition, which might be an effective adaptation for seed dispersal by animals. More importantly, we discovered that the northern limit of this genus, as well as those of two other arboreal taxa Metasequoia Miki ex Hu et Cheng (gymnosperm) and Nordenskioldia Heer (angiosperm), migrated ca.4-5° southward in paleolatitude during this time interval. CONCLUSIONS: Our results suggest that the cooling during the K-Pg transition may have been responsible for the increase in size of the seed cone of Mesocyparis and have driven the migration of plants southwards.

Organisation(s)
Department of Palaeontology
External organisation(s)
Chinese Academy of Sciences (CAS)
Journal
BMC Plant Biology
Volume
19
No. of pages
11
ISSN
1471-2229
DOI
https://doi.org/10.1186/s12870-019-1980-y
Publication date
09-2019
Peer reviewed
Yes
Austrian Fields of Science 2012
105118 Palaeontology
Keywords
ASJC Scopus subject areas
Plant Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/43ab8d5b-6be4-4ef4-af3c-09f351c8992d