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Gomphotheres arrived in South America during the “Great American Biotic Interchange” and occurred in South America from the early middle Pleistocene (Ensenadan Land-mammal Age) to the late Pleistocene (Lujanian Land-mammal Age). Only two genera are recognized: (1) Cuvieronius, which has only one species, Cuvieronius hyodon; and (2) Stegomastodon, which has two species, Stegomastodon waringi and Stegomastodon platensis. The small Cuvieronius utilized the Andean corridor and was almost exclusively a mixed-feeder. The large Stegomastodon dispersed through the East route and the coastal area. Stegomastodon waringi showed an adaptive trend from mixed-feeder to grazer, while Stegomastodon platensis showed a trend from mixed to browser feeding. Cuvieronius seems to have been adapted to temperate-cold climate conditions, while Stegomastodon appears to have predominated in lower latitudes, and was better adapted to warm or temperate climatic conditions. [Copyright &y& Elsevier]

Venta Micena (Orce, Guadix-Baza Basin, Spain) is an Early Pleistocene locality renowned for the richness and quality of its palaeontological record. VM is spread over an area of 2.5 km2, where several exposed fossil outcrops are visible amidst its gorges and ravines. The best known of these sites, VM3, has been interpreted as a hyaena den. In addition, a new site, named VM4, has recently been the focus of fieldwork and taphonomic studies. The publication by Luzón et al. (2021) pointed out that VM4 presents a more complex history than VM3. First, two different sub-levels were identified: VM4-I and VM4-II. Secondly, the preliminary taphonomic analysis showed conspicuous differences with regard to VM3. Nevertheless, such interpretation has been challenged by Palmqvist et al. (2022) who proposed that VM3 and VM4 are both the result of a single depositional process, entailing the selective transport of skeletal parts by the giant extinct hyaena Pachycrocuta brevirostris back to its den. Using well-preserved faunal elements whose depositional context and provenance are reliable, in this paper we show that: 1) there are two clearly defined sub-levels in VM4 with some shared taphonomic characteristics as well as some notable differences; 2) VM3 and VM4 exhibit enough divergence to support differences in site formation processes; 3) The interpretation of both VM4-I and VM4-II is more consistent with their characterisation as open-air sites in which multiple agents and depositional processes contributed to its formation, rather than with hyaena dens. Nevertheless, excavations are still in progress at VM4 and therefore any results and interpretations ought to be considered as provisional. • VM3 has been interpreted as a hyaena den. • VM4 presents a more complex history than VM3. • VM4-II, is more consistent with an open-air site. • VM4 is not a carnivore den site. [ABSTRACT FROM AUTHOR]

Global climate shifts and ecological flexibility are two major factors that may affect rates of speciation and extinction across clades. Here, we connect past climate to changes in diet and diversification dynamics of ruminant mammals. Using novel versions of Multi-State Speciation and Extinction models, we explore the most likely scenarios for evolutionary transitions among diets in this clade and ask whether ruminant lineages with different feeding styles (browsing, grazing and mixed feeding) underwent differential rates of diversification concomitant with global temperature change. The best model of trait change had transitions from browsers to grazers via mixed feeding, with appreciable rates of transition to and from grazing and mixed feeding. Diversification rates in mixed-feeder and grazer lineages tracked the palaeotemperature curve, exhibiting higher rates during the Miocene thermal maxima. The origination of facultative mixed diet and grazing states may have triggered two adaptive radiations--one during the Oligocene-Miocene transition and the other during Middle-to-Late Miocene. Our estimate of mixed diets for basal lineages of both bovids and cervids is congruent with fossil evidence, while the reconstruction of browser ancestors for some impoverished clades--Giraffidae and Tragulidae--is not. Our results offer model-based neontological support to previous palaeontological findings and fossil-based hypothesis highlighting the importance of dietary innovations--especially mixed feeding--in the success of ruminants during the Neogene.