Article: Permian and Early Triassic extinction of non-marine tetrapods
W. Desmond Maxwell
The non-marine tetrapods of the Permian and Early Triassic experienced four significant episodes of extinction during a time of relatively high turnover at the family level. The Artinskian, Ufimian, and Scythian extinctions appear genuine, but the Tatarian extinction is compromised by spurious data. The quality of the Tatarian data is considered in the light of the poor stratigraphical record for the Late Permian and Permian-Triassic boundary. Various extinction mechanisms are considered, bearing in mind that the radiation of the mammal-like reptiles forms a large portion of the diversity data. The most likely hypothesis is that non-marine tetrapods were subjected to environmental stress as climates fluctuated, at first in association with glaciation, and then with continental warming.