Asselian Age
The Asselian (298.9–293.5 Ma) is the first stage of the Early Permian (Cisuralian), as well as the Permian Period, occurring before the Sakmarian, and after the Gzhelian (Late Pennsylvanian)
Geologic Age
298.9±0.15–293.52±0.17 million years ago
Eon / Era / Period / Epoch
Left: Reconstruction of a fossil forest from 298 million years ago, found in Wuda, China
What happened during this time?
Biological
Flora, spore-bearing
Forests of scale trees, ferns, horsetails, progymnosperms, and seed ferns found in Chinese localities
The dominant trees are noeggerathian progymnosperms with an emergent layer of scale trees, such as Sigillaria in some areas
There are abundant marattialean tree ferns, as well as smaller zygopterid ferns
Sphenophyllophytes are found in the under-story and horsetails along rivers and wetlands
The earliest known true fern,Oligosporangiopteris zhongxiangii, has been found from the Inner Mongolia, North China (Frojdová et al. 2021)
Flora, seed-bearing
The Cordaitales diversify in Euramerica, and Glossopteridales diversify in Gondwana
Seed ferns, such as the Medullosales, Callistophytales, and Peltasperms were still on the landscape surviving from the Carboniferous
Medullosids had a (semi-)self-supporting growth habit with a high water-conducting potential of these plants, thriving under seasonally-dry climate on wet, rocky soils showing proximity to the groundwater level (Luthardt et al. 2021)
Giganopterids, complex seed ferns, were among the most striking and important plants of the Cathaysian flora of Sino-Malaya (Wang 1999)
The earliest record of ginkgophytes, Trichopitys, occurs during this time (Zhou 2009)
