When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa

Abstract

A mid-Permian (Guadalupian epoch) extinction event at approximately 260 Ma has been mooted for two decades. This is based primarily on invertebrate biostratigraphy of Guadalupian -Lopingian marine carbonate platforms in southern China, which are temporally constrained by correlation to the associated Emeishan Large Igneous Province (LIP). Despite attempts to identify a similar biodiversity crisis in the terrestrial realm, the low resolution of mid-Permian tetrapod biostratigraphy and a lack of robust geochronological constraints have until now hampered both the correlation and quantification of terrestrial extinctions. Here we present an extensive compilation of tetrapod-stratigraphic data analysed by the constrained optimization (CONOP) algorithm that reveals a significant extinction event among tetrapods within the lower Beaufort Group of the Karoo Basin, South Africa, in the latest Capitanian. Our fossil dataset reveals a 74 -80% loss of generic richness between the upper Tapinocephalus Assemblage Zone (AZ) and the mid-Pristerognathus AZ that is temporally constrained by a U-Pb zircon date (CA-TIMS method) of 260.259 + 0.081 Ma from a tuff near the top of the Tapinocephalus AZ. This strengthens the biochronology of the Permian Beaufort Group and supports the existence of a mid-Permian mass extinction event on land near the end of the Guadalupian. Our results permit a temporal association between the extinction of dinocephalian therapsids and the LIP volcanism at Emeishan, as well as the marine end-Guadalupian extinctions.

Integrated multi-stratigraphic study of the Coll de Terrers late Permian–Early Triassic continental succession from the Catalan Pyrenees (NE Iberian Peninsula): A geologic reference record for equatorial Pangaea

“…This climatic shift is possibly related to that of the upper portion of the Alcotas formation in the Iberian Basin (De la Horra et al, 2012) and also to the climatic shift documented in the early late Permian of northern Pangaea (Retallack et al, 2006;Roscher and Schneider, 2006;Słowakiewicz et al, 2009). This may imply that the lower/upper URU boundary could be correlated with the middle-late Capitanian (around the middle Permian extinction event) (Retallack et al, 2006;Sheldon et al, 2014;Day et al, 2015). Nevertheless, the lower/upper URU boundary possibly represents a paraconformity or sedimentary hiatus (i.e., long periods of exposition and development of levels with large nodules; Fig.…”

Refining the chronostratigraphy of the Karoo Basin, South Africa: magnetostratigraphic constraints support an early Permian age for the Ecca Group

“…1) represents an extensive depositional record of Pennsylvanian-early Jurassic fossiliferous sedimentary (Rubidge et al, 1999) rocks that have been critical for understanding the rate of vertebrate turnovers for continental extinction events during the End-Guadalupian and across the Permian-Triassic boundary (Botha and Smith, 2006;Day et al, 2015;Gastaldo et al, 2015;Rubidge et al, 2013;Smith and Botha, 2005;Smith and Botha-Brink, 2014;Smith and Ward, 2001;Ward et al, 2005). The excellent preservation of the associated vertebrate assemblages has led to a large library of published faunal information, complemented by palynological data, that has been extrapolated globally to understand the patterns of tetrapod extinctions and their timing relative to the end-Permian marine extinction at ca.…”

Late Permian (Lopingian) Terrestrial Ecosystems: A Global Comparison With New Data From the Low Latitude Bletterbach Biota

“…However, this correlation is complicated by the discovery at Serra do Cadeado of a tapinocephalid dinocephalian (Boos et al, 2015), which is a clade largely thought to occur only in the Guadalupian. The discovery of an Endothiodon species in likely Guadalupian strata in Tanzania (Angielczyk et al, 2014a;Cox and Angielczyk, 2015) and radiometric dates from the Karoo Basin suggest that the lower Pristerognathus zone is Guadalupian in age (Day et al, 2015). These issues raise questions about the Lopingian age assignment of the tetrapod-bearing horizons, given that they would imply the existence of a late-surviving dinocephalian, and also whether the localities sample a single fauna.…”

“…Correlations among these localities, and to strata in other basins, are obscure because of uncertainties in the exact stratigraphic relationships of the individual fossiliferous outcrops, and the fact that they preserve largely distinct faunal assemblages that include taxa with contradictory biostratigraphic implications (see reviews in Boos et al, 2013Boos et al, , 2015. The Serra do Cadeado localities frequently have been considered to be Lopingian in age, based on the presence of the dicynodont Endothiodon (Barberena et al, 1985;Langer, 2000;Cisneros et al, 2005;Dias-daSilva, 2012;Boos et al, 2013), which is found in the Lopingian Pristerognathus, Tropidostoma, and Cistecephalus Assemblage Zones of the Karoo Basin (e.g., Smith et al, 2012;Day et al, 2015). However, this correlation is complicated by the discovery at Serra do Cadeado of a tapinocephalid dinocephalian (Boos et al, 2015), which is a clade largely thought to occur only in the Guadalupian.…”

“…This vast basin covers more than half of the surface area of South Africa, and it contains a near-continuous stratigraphic record of the late Permian. Here we focus on the four biostratigraphic assemblage zones spanning the latest Capitanian to Changhsingian (Rubidge et al, 2013;Day et al, 2015;Gastaldo et al, 2015), at which time the Karoo was located around 60-65°S latitude (Scotese, 2003;Stampfli and Borel, 2004;Blakey, 2008). The depositional environment varies from large meandering channel belts to a network of numerous smaller channels with low sinuosity, punctuated by episodes of overbank sedimentation (e.g., Smith et al, 1993;Catuneanu et al, 2005;Prevec et al, 2010;Smith and Botha-Brink, 2014).…”