@article{kammerer_viglietti_butler_botha_2023, title={Rapid turnover of top predators in African terrestrial faunas around the Permian-Triassic mass extinction}, volume={33}, ISSN={["1879-0445"]}, DOI={10.1016/j.cub.2023.04.007}, abstractNote={Catastrophic ecosystem disruption in the late Permian period resulted in the greatest loss of biodiversity in Earth's history, the Permian-Triassic mass extinction (PTME).1 The dominant terrestrial vertebrates of the Permian (synapsids) suffered major losses at this time, leading to their replacement by reptiles in the Triassic.2 The dominant late Permian predatory synapsids, gorgonopsians, were completely extirpated by the PTME. The largest African gorgonopsians, the Rubidgeinae, have traditionally been assumed to go extinct at the Permo-Triassic boundary (PTB).3,4,5 However, this apparent persistence through the sustained extinction interval characterizing the continental PTME6 is at odds with ecological theory indicating that top predators have high extinction risk.7 Here, we report the youngest known large-bodied gorgonopsians, gigantic specimens from the PTB site of Nooitgedacht 68 in South Africa. These specimens are not rubidgeine, and instead are referable to Inostrancevia, a taxon previously thought to be a Russian endemic.8 Based on comprehensive review of the South African gorgonopsian record, we show that rubidgeines were early victims of ecosystem disruption preceding the PTME and were replaced as top predators by Laurasian immigrant inostranceviines. The reign of this latter group was short-lived, however; by the PTB, gorgonopsians were extinct, and a different group (therocephalians) became the largest synapsid predators, before themselves going extinct. The extinction and replacement of top predators in rapid succession at the clade level underlines the extreme degree of ecosystem instability in the latest Permian and earliest Triassic, a phenomenon that was likely global in extent.}, number={11}, journal={CURRENT BIOLOGY}, author={Kammerer, Christian F. and Viglietti, Pia A. and Butler, Elize and Botha, Jennifer}, year={2023}, month={Jun}, pages={2283-+} }
 @article{simoes_kammerer_caldwell_pierce_2022, title={Successive climate crises in the deep past drove the early evolution and radiation of reptiles}, volume={8}, ISSN={["2375-2548"]}, DOI={10.1126/sciadv.abq1898}, abstractNote={Climate change–induced mass extinctions provide unique opportunities to explore the impacts of global environmental disturbances on organismal evolution. However, their influence on terrestrial ecosystems remains poorly understood. Here, we provide a new time tree for the early evolution of reptiles and their closest relatives to reconstruct how the Permian-Triassic climatic crises shaped their long-term evolutionary trajectory. By combining rates of phenotypic evolution, mode of selection, body size, and global temperature data, we reveal an intimate association between reptile evolutionary dynamics and climate change in the deep past. We show that the origin and phenotypic radiation of reptiles was not solely driven by ecological opportunity following the end-Permian extinction as previously thought but also the result of multiple adaptive responses to climatic shifts spanning 57 million years.}, number={33}, journal={SCIENCE ADVANCES}, author={Simoes, Tiago R. and Kammerer, Christian F. and Caldwell, Michael W. and Pierce, Stephanie E.}, year={2022}, month={Aug} }
 @article{kammerer_rubidge_2022, title={The earliest gorgonopsians from the Karoo Basin of South Africa}, volume={194}, ISSN={["1879-1956"]}, DOI={10.1016/j.jafrearsci.2022.104631}, abstractNote={Therapsids underwent an explosive radiation in the middle Permian, with all but one of the major therapsid subclades appearing in the fossil record at this time. However, the therapsid subclade Gorgonopsia is rare in the middle Permian (in strong contrast to their late Permian record, where they are the dominant terrestrial vertebrate predators), and known mainly from Capitanian (latest middle Permian) strata in the Karoo Basin of South Africa. Here we present three previously undescribed middle Permian gorgonopsian specimens from earlier South African deposits, which constitute the earliest well-supported records of this group worldwide. The oldest known gorgonopsian specimen is a partial snout from the Eodicynodon Assemblage Zone (Wordian), nondiagnostic to species but identifiable as gorgonopsian based on septomaxillary morphology. Two partial skulls from the lowermost Tapinocephalus Assemblage Zone (late Wordian/early Capitanian) in the eastern Karoo represent a new taxon of gorgonopsian (Phorcys dubei gen. et sp. nov.) diagnosed by the autapomorphic presence of knob-like protuberances on the basioccipital between the basal tubera and occipital condyle. Inclusion of Phorcys in a phylogenetic analysis of Gorgonopsia recovers it in a weakly-supported basal position within the clade of African gorgonopsians. All three of the specimens described herein are substantially larger than previously known middle Permian gorgonopsians, suggesting that patterns of competition and replacement between gorgonopsians and coeval therocephalians were more complicated than previously thought.}, journal={JOURNAL OF AFRICAN EARTH SCIENCES}, author={Kammerer, Christian F. and Rubidge, Bruce S.}, year={2022}, month={Oct} }
 @article{kammerer_araujo_cumbane_macungo_smith_angielczyk_2021, title={New material of Dicynodon angielczyki (Synapsida: Anomodontia) from Mozambique and Zambia with biostratigraphic implications for African Permo-Triassic basins}, ISSN={["1937-2809"]}, DOI={10.1080/02724634.2021.2041652}, abstractNote={ABSTRACT Dicynodont therapsids are widely used in Permo-Triassic vertebrate biostratigraphy. However, recent taxonomic revisions have left few valid species with broad enough geographic distributions to use in establishing interbasinal correlations; instead, most currently recognized dicynodont species are basinal endemics. This is particularly true of the array of Permian dicynodontoids held in the formerly cosmopolitan wastebasket genus Dicynodon, now considered to mostly represent distinct (and in many cases distantly related) local taxa. As an example, Dicynodon fossils from the Ruhuhu Basin of Tanzania, formerly referred to “Dicynodon huenei,” have recently been separated out as a distinct species, Dicynodon angielczyki. Dicynodon angielczyki has been considered a Ruhuhu Basin endemic, as no records of this taxon are known in the extensive dicynodont sample from the Karoo Basin of South Africa. However, there has been little research on dicynodontoids from other upper Permian basins in eastern Africa, and their taxonomic composition is uncertain. Here, we describe the first specimens referable to D. angielczyki from other African sedimentary basins, demonstrating that this species is also present in the Metangula Graben of Mozambique and Luangwa Basin of Zambia. The new specimens permit improved correlations between the rock units of these basins as well as providing new information on the anatomy and possibly ontogeny of D. angielczyki.}, journal={JOURNAL OF VERTEBRATE PALEONTOLOGY}, author={Kammerer, Christian F. and Araujo, Ricardo and Cumbane, Keila and MaCungo, Zanildo and Smith, Roger M. H. and Angielczyk, Kenneth D.}, year={2021}, month={Nov} }