Premium
Mid‐Cretaceous Hothouse Climate and the Expansion of Early Angiosperms
Author(s) -
ZHANG Mingzhen,
DAI Shuang,
DU Baoxia,
JI Liming,
HU Shusheng
Publication year - 2018
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.13692
Subject(s) - cretaceous , aridification , terrestrial plant , red beds , terrestrial ecosystem , paleoclimatology , paleontology , geology , ecology , ecosystem , climate change , arid , biology
The remarkable transition of early angiosperms from a small to a dominant group characterized the terrestrial ecosystem of the Cretaceous. This transition was instigated and promoted by environmental changes. Mid‐Cretaceous is characterized by major geological events that affected the global environment. δ 18 O, palaeothermometer TEX 86 , and other climatic indices from marine sediments suggest rapid temperature increase during mid‐Cretaceous despite occasional short cooling events. Simultaneously, terrestrial deposits in East Asia changed from coal‐bearing to shale, then to red beds and evaporites. Plant assemblages and other paleoclimate indicators point to rapid aridification for mid‐Cretaceous terrestrial environments. In addition, the wildfires were frequently spread all over the earth by the numerous charcoal evidence during the Mid‐Cretaceous. Thus, we speculate that the seasonally dry and hot conditions of mid‐Cretaceous created a fiery hothouse world. Early angiosperms increased in abundance and diversity and evolved from a few aquatic species to terrestrial herbaceous and then to the diversified flora of today. Angiosperms showed rapid physiological evolution in vein density and leaf area that improved photosynthesis and water absorption. These ecophysiological changes made early angiosperms well adapted to the hot and dry environment in mid‐Cretaceous. Moreover, these physiological changes facilitated the fire–angiosperm cycles in mid‐Cretaceous that likely further stimulated the early angiosperm evolution.