The Parareptilia are a small but ecologically and morphologically diverse clade of Permian and Triassic crown amniotes generally considered to be phylogenetically more proximal to eureptiles (diapsids and their kin) than to synapsids (mammals and their kin). A recent supertree provides impetus for an analysis of parareptile diversity through time and for examining the influence of the endPermian mass extinction on the clade's origination and extinction rates. Phylogeny-corrected measures of diversity have a significant impact on both rates and the distribution of origination and extinction intensities. Time calibration generally results in a closer correspondence between origination and extinction rate values than in the case of no time correction. Near the end-Permian event, extinction levels are not significantly higher than origination levels, particularly when time calibration is introduced. Finally, regardless of time calibration and ⁄ or phylogenetic correction, the distribution of rates does not differ significantly from unimodal. The curves of rate values are discussed in the light of the numbers and distributions of both range extensions and ghost lineages. The disjoint time distributions of major parareptile clades (e.g. procolophonoids and nycteroleterids-pareiasaurs) are mostly responsible for the occurrence of long-range extensions throughout the Permian. Available data are not consistent with a model of sudden decline at the end-Permian but rather suggest a rapid alternation of originations and extinctions in a number of parareptile groups, both before and after the Permian ⁄ Triassic boundary.Key words: diversity, extinctions, originations, Parareptilia, Permian, Triassic, turnover.Mass extinctions provide the most dramatic example of large-scale biological crises on record. The modalities of decline, disappearance and ⁄ or recovery of different clades inform our understanding of the tempo and mode of ecosystem collapse and recovery and allow us to explore the interplay of biotic and abiotic factors in shaping clade diversification. Therefore, the study of mass extinctions is of great interest to palaeontologists, evolutionary biologists, and macroecologists (e.g. Benton 2003; Erwin 2006; Purvis 2008). However, the specific responses of individual groups to extinctions remain inadequately documented, particularly in the terrestrial domain. It is clear that some clades of plants and animals were minimally affected by these events, whilst others were hit to varying degrees. One of the challenges in the analysis of largescale extinctions is to integrate patterns that emerge for specific groups to understand how they contribute to broader local and global trends.Numerous papers have used tetrapods for case studies of the impact of the end-Permian mass extinction on land (in particular, see papers by Pitrat 1973; Benton 1987; Olson 1989; Milner 1990; Maxwell 1992; Modesto et al. 2001 Modesto et al. , 2003 Benton et al. 2004; Ward et al. 2005; Botha and Smith 2006; Retallack et al. 2006; ...

GEOLOGIC SETTINGToday, the Balearic Islands (Spanish: Islas Baleares; Catalan: Illes Balears; Fig. S1) represent the geomorphologically highest, and thus emergent, parts of the north-eastern extension of the Betic Cordillera of southern Spain. This extension is also called the Balearic Promontory, which to the northwest is separated from the Iberian mainland by the Valencia Trough, an Oligocene to recent extensional structure that has a complex tectonic history closely connected to the Alpidic collisional movements that affected the western Mediterranean realm in the Late Mesozoic and Cenozoic (Roca, 1996).The northwestern part of the Island of Mallorca is occupied by the Serra de Tramuntana (Serra del Nord), a southwest-northeast trending horst-like structure that internally is built up of southeast-dipping Alpidic thrust sheets of unmetamorphosed, predominantly calcareous rocks of Jurassic age. Exposures of Permian to Middle Triassic terrestrial redbeds (so-called 'Permo-Triassic') are present only at the northwestern flank of the Serra de Tramuntana in the coastal area between the villages of Estellencs and Valldemosa. These deposits were referred to as 'Buntsandstein facies' (Rodríguez-Perea et al., 1987) and subdivided into three units which are named, from oldest to youngest, 'Areniscas y Lutitas de Port des Canonge', 'Areniscas de Asá', and 'Lutitas y Areniscas de Son Serralta' (Ramos, 1995). They represent the infill of postvariscan northwest-southeast trending extensional structures whose origin is closely related to that of the Permo-Triassic basins of the Iberian Chain (Gomez-Gras, 1993). The source area of the redbeds was the Hesperian Massif -the Iberian part of the Variscan mountains -to the northwest, and deposition took place under semi-arid conditions (Ramos, 1995;Linol et al., 2009).The relative age of the 'Areniscas y Lutitas de Port des Canonge' (for convenience hereafter referred to as Port des Canonge beds) is not well constrained and depends on whether its top is considered a major unconformity or not. Ramos and Doubinger (1989) identified a Late Permian ('Thuringian') palynoflora in the middle part of the overlying Asá beds and consequently also assigned the Port des Canonge beds to the Upper Permian.