A complete sabertooth cat cranium from the Midcontinent of North America and its evolutionary and ecological context Matthew G. Hill a, * , David A. Easterla b a Iowa State University, Ames, USA b Maryville, Missouri, USA article info Article history: Received 1 August 2022 Received in revised form 12 March 2023 Accepted 12 March 2023 Available online xxx Handling Editor: C. Hillaire-Marcel Keywords: Felidae Rancholabrean Late quaternary extinctions Taphonomy abstract Outside of Rancho La Brea, southern California, United States, knowledge of the life history, ecology, and extinction of large, late Pleistocene carnivores in North America is frustrated by a scarcity of skeletal material and trustworthy radiocarbon dates. A complete Smilodon fatalis (sabertooth cat) cranium from southwestern Iowa, directly AMS radiocarbon dated to 11,685 ± 40 B.P. (13,605e13,455 cal B.P.), repre- sents an important addition to the inventory of evidence for the taxon in the Midcontinent. Assessment of tooth eruption and wear combined with metric and nonmetric comparisons with coeval crania from Pit 61/67 at Rancho La Brea indicates the specimen belongs to a subadult male 2e3 years of age at death. Craniodental morphology falls within the range of variation in the Pit 61/67 males. Predicted live weight is 251 kg. One C 1 has an antemortem bend fracture, and the absence of use-wear on the proximal remnant suggests death ensued within days of the injury. The radiocarbon date centers the animal in the Bølling-Allerød Chronozone (14,640e12,845 cal B.P.). Whereas regional conditions were generally warmer and wetter during this period, southwestern Iowa was a cool, dry non-analog boreal grassland/ parkland that supported a diverse, large herbivore community, including Megalonyx jeffersonii (Jeffer- son's ground sloth), the taxon tentatively identified in this study as the focal prey. Bayesian modeling of 72 direct radiocarbon dates for the taxon suggests extinction of the late Quaternary Smilodon was a hemispheric and geologically synchronic phenomenon that occurred after 13,285 cal B.P. Subjects: vertebrate paleontology, paleoecology, paleozoology. © 2023 Elsevier Ltd. All rights reserved. 1. Introduction Food-web scaling relationships coupled with taphonomic fac- tors make remains of large, late Pleistocene carnivores rare finds in the North American fossil record. Notable exceptions to this general rule include Rancho La Brea, California (Marcus, 1960; Merriam and Stock, 1932), Natural Trap Cave, Wyoming (Meachen and McGuire, 2023; Wang and Martin, 1993; Wheeler and Jefferson, 2009), and Friesenhahn Cave, Texas (Graham, 1976; Graham et al., 2013). At these locations, Felidae, Ursidae, and/or Canidae occur in abun- dance (and in association with other taxa). The more common pattern is isolated finds or small samples of fragmentary bones and teeth from primary and secondary contexts, and sometimes in as- sociation with other taxa. In these instances, cross-dating, strati- graphic observations, or faunal associations often supply rough, indirect ages for this material (and are adequate for addressing some questions). Excepting Rancho La Brea, the sample of reliable direct dates for these taxa is small, particularly east of the Rocky Mountains, where, for example, some eleven assays are available for Arctodus simus (giant short-faced bear) (Schubert, 2010) and one for Homotherium serum (scimitar cat) (Widga et al., 2012). Aenocyon dirus (dire wolf), the most common large carnivore on the land- scape (Dundas, 1999), has only recently been directly dated (Perri et al., 2021; Widga et al., 2017 , Table 4); and, heretofore, Smilodon fatalis (sabertooth cat). The scarcity of foundational evidence on carnivores poses analytical challenges to pursuing integrated questions about late Pleistocene megafaunal ecology in the region, from community structure, population fluctuations, and trophic connections to the drivers of extinction. Outside of Rancho La Brea, the inventory of S. fatalis material dating to the late Quaternary (defined here as falling within the range of radiocarbon dating methods) (50,000 years) (Bell et al., 2004, 287) is mostly isolated teeth, tooth rows, and partial crania from widely dispersed locations. Of the 67 records mapped in Fig. 1 , * Corresponding author. E-mail address: mghill@iastate.edu (M.G. Hill). Contents lists available at ScienceDirect Quaternary Science Reviews journal homepage: www.elsevier.com/locate/quascirev https://doi.org/10.1016/j.quascirev.2023.108045 0277-3791/© 2023 Elsevier Ltd. All rights reserved. Quaternary Science Reviews 307 (2023) 108045