Robert A. Gastaldo, the Whipple-Coddington Professor of Geology, Emeritus, has published a paper 10 years in the making in the Geological Society of America Bulletin. Titled “A tale of two Tweefonteins: What physical correlation, geochronology, magnetic polarity stratigraphy, and palynology reveal about the end-Permian terrestrial extinction paradigm in South Africa,” the paper offers results to settle the debate of whether or not there were pre-extinction or post-extinction unique groups of animals during the end-Permian extinction.

Gastaldo’s interdisciplinary team provides several sets of independent evidence demonstrating that there was no extinction of land animals as widely held in the literature. This finding has implications for modeling how terrestrial animals and plants might respond to our current climate challenges of rising temperatures and increasing C02 levels. That means, Gastaldo said, that “we no longer have a model for how life on land, particularly the animals, responded to changing climates and conditions on Earth during what has been called the ‘Mother of Mass Extinction’ events.” 

The paper is the culmination of 10 years of research that began with several undergraduate projects in a locality called Tweefontein (two springs) in South Africa’s Karoo Basin. The geology majors who first worked on these rocks were Mduduzi Langwenya ’14, Kody Spencer ’14J, and Tara Chizinski ’14. Subsequent to their graduation, Kathy Trafton ’16, Jiawen Li ’16, Takuto Sasijama ’16, along with Sam Sinkler ’18 and Kaci Kus ’18, were instrumental in both field and laboratory studies, several of which resulted in honors projects and coauthored publications.