We describe new carnivoran fossils from Kalodirr and Moruorot, two late Early

Miocene sites in the Lothidok Formation of West Turkana, Kenya. The fossils include a

new species of viverrid, Kichechia savagei  sp. nov., a new genus and species of felid,

Katifelis nightingalei  gen. et sp. nov., and an unidentified musteloid. We also report

new records of the amphicyonid Cynelos macrodon. These new fossils increase the

known diversity of African Early Miocene carnivorans and highlight regional differences

in Africa.

Sabre-like canines clearly have the potential to inflict grievous wounds leading to massive blood loss and rapid death. Hypotheses concerning sabretooth killing modes include attack to soft parts such as the belly or throat, where biting deep is essential to generate strikes reaching major blood vessels. Sabretoothed carnivorans are widely interpreted as hunters of larger and more powerful prey than that of their present-day nonsabretoothed relatives. However, the precise functional advantage of the sabretooth bite, particularly in relation to prey size, is unknown. Here, we present a new point-to-point bite model and show that, for sabretooths, depth of the killing bite decreases dramatically with increasing prey size. The extended gape of sabretooths only results in considerable increase in bite depth when biting into prey with a radius of less than ~10 cm. For sabretooths, this size-reversed functional advantage suggests predation on species within a similar size range to those attacked by present-day carnivorans, rather than “megaherbivores” as previously believed. The development of the sabretooth condition appears to represent a shift in function and killing behaviour, rather than one in predator-prey relations. Furthermore, our results demonstrate how sabretoothed carnivorans are likely to have evolved along a functionally continuous trajectory: beginning as an extension of a jaw-powered killing bite, as adopted by present-day pantherine cats, followed by neck-powered biting and thereafter shifting to neck-powered shear-biting. We anticipate this new insight to be a starting point for detailed study of the evolution of pathways that encompass extreme specialisation, for example, understanding how neck-powered biting shifts into shear-biting and its significance for predator-prey interactions. We also expect that our model for point-to-point biting and bite depth estimations will yield new insights into the behaviours of a broad range of extinct predators including therocephalians (gorgonopsian + cynodont, sabretoothed mammal-like reptiles), sauropterygians (marine reptiles) and theropod dinosaurs.

Sediments of the Bahe and Lantian formations, Lantian area, Shaanxi Province, China, have produced a large number of mammalian fossils. This Late Miocene sequence provides evidence for a period of major changes in the physical environment of the region. The carnivoran fossils are described and analyzed herein. The following species are present: lctitherium viverrinum, Hyaenictitherium cf . H. wongii and Adcrocuta eximia ( Hyaenidae) , cf. Metailurus major and cf. Metailurus parvulus ( Felidae) . Although a difference in the composition of the carnivoran fauna is noted towards the boundary between the Bahe Formation (lower) and Lantian Formation (upper), the cause of this is yet to be determined.

Eight years of excavation work by the Olduvai Geochronology and Archaeology Project (OGAP) has produced a rich vertebrate fauna from several sites within Bed II, Olduvai Gorge, Tanzania. Study of these as well as recently re-organized collections from Mary Leakey's 1972 HWK EE excavations here provides a synthetic view of the faunal community of Olduvai during Middle Bed II at ~1.7e1.4 Ma, an interval that captures the local transition from Oldowan to Acheulean technology. We expand the faunal list for this interval, name a new bovid species, clarify the evolution of several mammalian lineages, and record new local first and last appearances. Compositions of the fish and large mammal assemblages support previous indications for the dominance of open and seasonal grassland habitats at the margins of an alkaline lake. Fish diversity is low and dominated by cichlids, which indicates strongly saline conditions. The taphonomy of the fish assemblages supports reconstructions of fluctuating lake levels with mass die-offs in evaporating pools. The mammals are dominated by grazing bovids and equids. Habitats remained consistently dry and open throughout the entire Bed II sequence, with no major turnover or paleoecological changes taking place. Rather, wooded and wet habitats had already given way to drier and more open habitats by the top of Bed I, at 1.85e1.80 Ma. This ecological change is close to the age of the Oldowan-Acheulean transition in Kenya and Ethiopia, but precedes the local transition in Middle Bed II. The Middle Bed II largemammal community is much richer in species and includes a much larger number of large-bodied species (>300 kg) than the modern Serengeti. This reflects the severity of Pleistocene extinctions on African large mammals, with the loss of large species fitting a pattern typical of defaunation or ‘downsizing’ by human disturbance. However, trophic network (food web) analyses show that the Middle Bed II communitywas robust, and comparisons with the Serengeti community indicate that the fundamental structure of foodwebs remained intact despite Pleistocene extinctions. The presence of a generalized meateating hominin in the Middle Bed II community would have increased competition among carnivores and vulnerability among herbivores, but the high generality and interconnectedness of the Middle Bed II food web suggests this community was buffered against extinctions caused by trophic interactions.

Kelba quadeemae, a fossil mammal from the Early Miocene of East Africa, was originally named on the basis of three isolated upper molars. Kelba has previously been interpreted as a creodont, a pantolestid, an insectivoran, and a hemigaline viverrid. The true affinities of this taxon have remained unclear because of the limited material and its unique morphology relative to other Miocene African mammals. New material of Kelba from several East African Miocene localities, most notably a skull from the Early Miocene locality of Songhor in Western Kenya, permits analysis of the affinities of Kelba and documents the lower dentition of this taxon. Morphological comparison of this new material clearly demonstrates that Kelba is a member of the order Ptolemaiida, a poorly understood group whose fossil record was previously restricted to the Oligocene Fayum deposits of northern Egypt. Phylogenetic analysis supports the monophyly of the Ptolemaiida, including Kelba, and recovers two monophyletic clades within the order. We provide new family names for these groups and an emended diagnosis for the order. The discovery of ptolemaiidans from the Miocene of East Africa is significant because it extends the known temporal range of the order by >10 million years and the geographic range by >3,200 km. Although the higher-level affinities of the Ptolemaiida remain obscure, their unique morphology and distribution through a larger area of Africa (and exclusively Africa) lend support to the idea that Ptolemaiida may have an ancient African origin.

Motivation

Body mass is one of the most important determinants of animal ecology. Unlike other important traits it is also readily inferable from fossils and it is therefore one of the only traits that can be directly analysed and compared between fossil and contemporary communities. Despite this, no comprehensive database of the body mass of larger clades of extinct species exists. Analysis of fossils has therefore been restricted to small clades or to smaller, potentially biased, subsets of species. We here describe CarniFoss, an open-access database of body masses of all 1,322 extinct species of non-pinniped Carnivoramorpha and two related extinct groups of carnivorous mammals, Hyaenodonta and Oxyaenidae.

Main types of variables contained

We gathered lengths of teeth of fossil and extant species and body mass for extant species and a few of the best-known fossil species. Following this we estimated body mass for all species through phylogenetic imputation.

Spatial location and grain

Global, terrestrial.

Time period and grain

We collected data on all known species within the focal groups. The known species all lived in the Palaeogene, Neogene or Quaternary (i.e., the last 66 Myr).

Major taxa and level of measurement

We searched for data on reported tooth size of all described species of Carnivoramorpha (excluding pinnipeds) and selected extinct related groups (Hyaenodonta and Oxyaenidae). We combined this with measured body mass for all extant species and inferred body mass based on long-bones for selected extinct species, as well as a species-level phylogeny including all extant and extinct species in the group, and inferred the body mass for all species using phylogenetic imputation.

Software format

Data are provided as a series of .csv files, with all metadata in a separate PDF file.

While the anthropogenic impact on ecosystems today is evident, it remains unclear if the detrimental

effect of hominins on co-occurring biodiversity is a recent phenomenon or has also been

the pattern for earlier hominin species. We test this using the East African carnivore fossil record.

We analyse the diversity of carnivores over the last four million years and investigate whether any

decline is related to an increase in hominin cognitive capacity, vegetation changes or climatic

changes. We find that extinction rates in large carnivores correlate with increased hominin brain

size and with vegetation changes, but not with precipitation or temperature changes. While temporal

analyses cannot distinguish between the effects of vegetation changes and hominins, we

show through spatial analyses of contemporary carnivores in Africa that only hominin causation

is plausible. Our results suggest that substantial anthropogenic influence on biodiversity started

millions of years earlier than currently assumed.

The evolution of the brain at the origin of Carnivora remains poorly understood, largely owing to the limited number of cranial endocasts known from Carnivoramorpha and basal crown Carnivora. Here, we use x-ray computed tomography to create digital endocasts of two early carnivores, Quercygale angustidens and Gustafsonia cognita. Quercygale angustidens is generally regarded as the sister taxon to Carnivora and Nimravidae and is thus of great interest to further our understanding of the evolutionary changes that occurred at the origin of Carnivora. Gustafsonia cognita provides a comparison to a contemporary crown carnivoran. We describe the endocasts of these two taxa, placing them in the context of carnivoramorphan phylogeny. Both endocasts preserve the cerebellum in great detail, resulting in a better understanding of the morphology of this part of the brain in early carnivores. Gustafsonia cognita, despite its small size, geological age and basal position, displays a sulcal pattern typical of Amphicyonidae, reaffirming its position within the family. Nimravids; and early carnivorans, such as Gustafsonia cognita, Proailurus lemanensis and Hesperocyon gregarius, have more expanded neocortices than Quercygale angustidens. Current evidence suggests that the increase in gyrification in basal Carnivoramorpha occurred mainly through elongation of existing sulci and entered a new phase at the origin of crown Carnivora. Additional sulci appeared in early members of the order, resulting in distinctive sulcal patterns in the different carnivoran families. Nevertheless, more endocasts of basal carnivorans and carnivoramorphans are needed to better understand the processes driving the evolution of the brain in this group.

We have recently reviewed the later Miocene (MN 6-13; ca 15-5 Ma ago) primates, hipparions, rhinocerotids, suoids and carnivores of Europe and the eastern Mediterranean. This work is still unpublished and analyses are underway, but a preliminary indication of some coarse patterns is given here for the sample consisting of the groups listed above: 1) There is a clear-cut difference between western and Central Europe on one hand and the eastern Mediterranean on the other. This is especially clear for species richness, which shows a rising trend throughout the Vallesian and earlier Turolian for the eastern regions and a falling trend for the western ones. 2) The major drops in species richness occurred between MN 6 and MN 7, between MN 9 and MN 10, and between MN 12 and MN 13. Of these, the "mid-Vallesian crisis" (MN 9-10) seems to have been entirely absent in the eastern Mediterranean, where species richness rose sharply during this interval. Correspondingly, the drop in MN 12-13, associated with the Messinian crisis, was predominantly an eastern phenomenon. 3) Taxon free analysis of body size and ecomorphology strongly supports the view that a diachronous opening up of the landscape from east to west took place in western Eurasia during the Astaracian and Vallesian. We postulate that the difference seen in faunal dynamics between east and west reflects habitat-related effects of this diachrony in response to the same global event of rapid physical change. 4) The early Turolian (MN 11) was characterized by high diversity and high faunal similarity, which both decreased during the later Turolian and ended with the Messinian crisis. 5) Despite highly uniform diversity and turnover patterns throughout the interval, western and Central Europe developed distinct ecological differences from about MN 10 onwards. These differences may have been associated with the persistence of closed habitats in Central Europe.

The NOW database of fossil mammals came to be through a confluence of several initiatives spanning multiple decades. The first public version of NOW database was released in 1996 and the first Advisory Board was established the year after. Originally, NOW stood for Neogene of the Old World but with the gradual expansion of the database the acronym was eventually reassigned to stand for New and Old Worlds. The structure of what would become NOW was originally cloned from the ETE database of the Smithsonian Institution and the first NOW version accessible over the internet was a node of the ETE database. The first standalone, online version of NOW was launched in 2005 and the first formal steering group was established in 2009. During its existence, NOW has been funded, directly or indirectly, by several organizations but fundamentally it has always been an unfunded community effort, dependent on voluntary work by the participants.

Although ecometric methods have been used to analyse fossil mammal faunas and environments of Eurasia and North America, such methods have not yet been applied to the rich fossil mammal record of eastern Africa. Here we report results from analysis of a combined dataset spanning east and west Turkana from Kenya between 7 and 1 million years ago (Ma). We provide temporally and spatially resolved estimates of temperature and precipitation and discuss their relationship to patterns of faunal change, and propose a new hypothesis to explain the lack of a temperature trend. We suggest that the regionally arid Turkana Basin may between 4 and 2 Ma have acted as a ‘species factory’, generating ecological adaptations in advance of the global trend. We show a persistent difference between the eastern and western sides of the Turkana Basin and suggest that the wetlands of the shallow eastern side could have provided additional humidity to the terrestrial ecosystems. Pending further research, a transient episode of faunal change centred at the time of the KBS Member (1.87–1.53 Ma), may be equally plausibly attributed to climate change or to a top-down ecological cascade initiated by the entry of technologically sophisticated humans.

The 1.977 Ma site of ‘Malapa’ (Gauteng, South Africa) has yielded important new fossils, including the type specimens of the new hominin species Australopithecus sediba. Recently, we reported the first Carnivora specimens to have been recovered from the site. That sample included members of Felidae, Herpestidae and Hyaenidae. That first report also included three associated small canid specimens (an M2, a rib and a posterior mandibular fragment including the P4, M1, coronoid, condylar and angular processes) that we attributed to Vulpes cf. V. chama. In this paper, we compare these specimens to a broad sample of modern and fossil foxes and conclude that these specimens are distinct enough to be referred to a new species, here described and named Vulpes skinneri.

African wild dogs (Lycaon pictus) occupy an ecological niche characterized by hypercarnivory and cursorial hunting. Previous interpretations drawn from a limited, mostly Eurasian fossil record suggest that the evolutionary shift to cursorial hunting preceded the emergence of hypercarnivory in the Lycaon lineage. Here we describe 1.9–1.0 ma fossils from two South African sites representing a putative ancestor of the wild dog. The holotype is a nearly complete maxilla from Coopers Cave, and another specimen tentatively assigned to the new taxon, from Gladysvale, is the most nearly complete mammalian skeleton ever described from the Sterkfontein Valley, Gauteng, South Africa. The canid represented by these fossils is larger and more robust than are any of the other fossil or extant sub-Saharan canids. Unlike other purported L. pictus ancestors, it has distinct accessory cusps on its premolars and anterior accessory cuspids on its lower premolars–a trait unique to Lycaon among living canids. However, another hallmark autapomorphy of L. pictus, the tetradactyl manus, is not found in the new species; the Gladysvale skeleton includes a large first metacarpal. Thus, the anatomy of this new early member of the Lycaon branch suggests that, contrary to previous hypotheses, dietary specialization appears to have preceded cursorial hunting in the evolution of the Lycaon lineage. We assign these specimens to the taxon Lycaon sekowei n. sp.

 Stable isotope palaeoecology of fossil mammals is a key research tool for understanding the environmental context of hominin evolution in the Plio-Pleistocene of Africa. Well studied mammal groups include bovids, suids, equids, proboscideans and primates, but to date there has been no in-depth study of modern and fossil carnivores. Here we produce an Africa-wide oxygen and carbon enamel isotope dataset for modern carnivores and compare it with fossil carnivore data sampled from the Plio-Pleistocene Omo Group of the Turkana Basin, Kenya. Comparison of modern carnivore carbon isotopes with satellite images of land cover indicates that carnivore δ13C is related to the proportion of woody cover in the local environment. Modern carnivore oxygen isotopes are strongly influenced by the δ18O of meteoric water, through drinking from standing water and through prey body fluids. Carbon isotope data from fossil carnivores shows close agreement with palaeovegetation reconstructions from δ13C of palaeosol carbonates from the same geological Members, and a similar long-term trend in δ13C values through time (4 Ma to 1 Ma), reflecting a gradual increase in the proportion of C4 grasses in the Turkana Basin. This increase in the δ13C of large carnivores is consistent with the evidence from other mammalian groups for an increase in the proportion of grazers compared to browsers and mixed feeders during this time interval. Two distinct trends within oxygen versus carbon isotope space indicates that the fossil carnivores lived during two distinct climatic regimes – one in which palaeo-lake Turkana was freshwater, and one in which the lake resembled its modern-day hyperalkaline state. These two climatic states most likely represent the end-members of precessionally-driven rainfall extremes over the Ethiopian Highlands. This indicates that each studied faunal assemblage from the Omo Group is a time- and climate-averaged palimpsest; this has significant implications for the interpretation of environmental signals and community palaeoecology derived from Turkana Basin fossil mammals, including early hominins. 

Stable isotope palaeoecology of fossil mammals is a key research tool for understanding the environmental context of hominin evolution in the Plio-Pleistocene of Africa. Well studied mammal groups include bovids, suids, equids, proboscideans and primates, but to date there has been no in-depth study of modern and fossil carnivores. Here we produce an Africa-wide oxygen and carbon enamel isotope dataset for modern carnivores and compare it with fossil carnivore data sampled from the Plio-Pleistocene Omo Group of the Turkana Basin, Kenya. Comparison of modern carnivore carbon isotopes with satellite images of land cover indicates that carnivore δ13C is related to the proportion of woody cover in the local environment. Modern carnivore oxygen isotopes are strongly influenced by the δ18O of meteoric water, through drinking from standing water and through prey body fluids. Carbon isotope data from fossil carnivores shows close agreement with palaeovegetation reconstructions from δ13C of palaeosol carbonates from the same geological Members, and a similar long-term trend in δ13C values through time (4 Ma to 1 Ma), reflecting a gradual increase in the proportion of C4 grasses in the Turkana Basin. This increase in the δ13C of large carnivores is consistent with the evidence from other mammalian groups for an increase in the proportion of grazers compared to browsers and mixed feeders during this time interval. Two distinct trends within oxygen versus carbon isotope space indicates that the fossil carnivores lived during two distinct climatic regimes – one in which palaeo-lake Turkana was freshwater, and one in which the lake resembled its modern-day hyperalkaline state. These two climatic states most likely represent the end-members of precessionally-driven rainfall extremes over the Ethiopian Highlands. This indicates that each studied faunal assemblage from the Omo Group is a time- and climate-averaged palimpsest; this has significant implications for the interpretation of environmental signals and community palaeoecology derived from Turkana Basin fossil mammals, including early hominins.

The tribe Machairodontini is a major lineage of felid sabertooth cats that flourished in the late Cenozoic and included the top predators in the ecosystem of that time. As top predators members of the tribe had a profound influence on the paleoenvironment, yet the evolution and diversification of this tribe are unclear due to a lack of comprehensive revision and phylogenetic study. Here we describe a new dwarfed ecomorph of Machairodontini, Taowu liui gen. et sp. nov., from the Early Pleistocene of northern China,and carry out the best sampled phylogeny of the subfamily to date. Our analyses support that the African Mio-Pleistocene Lokotunjailurus represents an early divergent group, convergent with the Amphimachairodus-Homotheriina lineage in dental traits. The derived Pliocene to Pleistocene subtribe Homotheriina originated in Africa, from Adeilosmilus gen. nov. kabir or very a closely related taxon. Taowu liui gen. et sp. nov. belongs to a sister clade to Homotheriina. The Plio-Pleistocene Homotheriina of theNew World belong to a monophyletic group in which Ischyrosmilus-Xenosmilus show a gradual adaptation to handling slow and powerful prey, whereas the true Homotherium only appeared after theMiddle Pleistocene, in a separate intercontinental dispersal event.

 1. The current classification of the Felidae was reviewed by a panel of 22 experts divided into core, expert and review groups, which make up the Cat Classification Task Force CCTF of the IUCN Cat Specialist Group.

2. The principal aim of the CCTF was to produce a consensus on a revised classification of the Felidae for use by the IUCN.

3. Based on current published research, the CCTF has fully revised the classification of the Felidae at the level of genus, species and subspecies.

4. A novel traffic-light system was developed to indicate certainty of each taxon based on morphological, molecular, biogeographical and other evidence. A concordance of good evidence in the three principal categories was required to strongly support the acceptance of a taxon.

5. Where disagreements exist among members of the CCTF, these have been highlighted in the accounts for each species. Only further research will be able to answer the potential conflicts in existing data.

6. A total of 14 genera, 41 species and 80 subspecies are recognised by most members of the CCTF, which is a considerable change from the classification proposed by Wozencraft (2005), the last major revision of the Felidae.

7. Future areas of taxonomic research have been highlighted in order to answer current areas of uncertainty.

8. This classification of the Felidae will be reviewed every five years unless a major new piece of research requires a more rapid revision for the conservation benefit of felid species at risk of extinction.

Recent discoveries at the new hominin-bearing deposits of Malapa, South Africa, have yielded a rich faunal assemblage associated with the newly described hominin taxon Australopithecus sediba. Dating of this deposit using U-Pb and palaeomagnetic methods has provided an age of 1.977 Ma, being one of the most accurately dated, time constrained deposits in the Plio-Pleistocene of southern Africa. To date, 81 carnivoran specimens have been identified at this site including members of the families Canidae, Viverridae, Herpestidae, Hyaenidae and Felidae. Of note is the presence of the extinct taxon Dinofelis cf. D. barlowi that may represent the last appearance date for this species. Extant large carnivores are represented by specimens of leopard (Panthera pardus) and brown hyaena (Parahyaena brunnea). Smaller carnivores are also represented, and include the genera Atilax and Genetta, as well as Vulpes cf. V. chama. Malapa may also represent the first appearance date for Felis nigripes (Black-footed cat). The geochronological age of Malapa and the associated hominin taxa and carnivoran remains provide a window of research into mammalian evolution during a relatively unknown period in South Africa and elsewhere. In particular, the fauna represented at Malapa has the potential to elucidate aspects of the evolution of Dinofelis and may help resolve competing hypotheses about faunal exchange between East and Southern Africa during the late Pliocene or early Pleistocene.

The initial dispersal of humans out of Africa was a significant event in human evolution raising many questions. Why did this happen at this particular time? Was it part of a major migration of mammals out of Africa and did any species move into Africa at the same time? Were climate and habitat changes taking place that might have been contributing factors? With the advent of culture at 2.6 Ma, hominins moved from the primate to the carnivore feeding niche, thus avoiding constraints that had previously determined their distribution. Here we look at fossil carnivores and cercopithecids for factors that provide a background to this significant event in our evolutionary history and we also look at herbivore diversity as a potential source of prey for meat-eating hominins.

 Carnivorans and hominins share a long history of interactions. This paper examines some of the evidence for carnivoran migration out of Africa at the same time as the earliest hominin dispersals. Of the two relevant taxa, Crocuta  and Megantereon , Megantereon  is the focus of this paper due to increased interest in this taxon in recent years and to the nature of the earliest records of dispersal of these two taxa, raising several questions related to Megantereon  and its possible influence on hominins. To answer these questions, a brief summary of the literature on Megantereon  in Eurasia and Africa is provided. While researchers do not agree on the number of species of Megantereon  or the evolutionary relationships among those species, most would agree that Megantereon  is a hypercarnivorous predator capable of grappling with relatively large prey for its body size. Despite the fact that carcasses generated by Megantereon  were probably of value to hominins, the hypotheses that these carcasses were a major source of food or that they were a major force enabling hominins to migrate out of Africa are rejected. As indicated in the literature on extant carnivorans, kleptoparasitism (= food theft) by dominant members of a carnivore guild exacts a heavy price on lower ranking carnivores. In addition, there is nothing in the African fossil record to suggest a special relationship between Megantereon  and hominins that did not exist between hominins and other large-bodied carnivorans. The hypothesis that a species of Megantereon  migrated out of Africa at roughly the same time as early hominins is also considered. While this hypothesis cannot be rejected, alternative hypotheses to explain similarities between later African and Eurasian forms of Megantereon  are proposed (e.g., shared characters are due to convergence or are symplesiomorphies). In the end, the small number of diverse African species (including hominins) who disperse into Eurasia at the Plio- Pleistocene transition may have been part of a sweepstakes dispersal where the factors permitting (or driving) dispersal may have differed from species to species.

This paper uses changes in origination and extinction rates and species richness of eastern African carnivorans through time to discuss issues related to the evolution of hominin behavior. To address the question of which taxa were most likely to have had competitive interactions with hominins, modern carnivorans were sorted into size classes based on shifts in behavior, ecology, and body mass. Four size classes were created, among which the two largest (21.5–100 kg and >100 kg) include those taxa whose behavior is most relevant to the evolution of hominin dietary behavior. Fossil taxa were then assigned to these size classes. A summary of the temporal range and reconstructed behavior and ecology of fossil members of the two largest size classes is presented. We discuss the relevance of each taxon to reconstructing hominin behavior and suggest that hominins must have evolved not only successful anti-predator strategies, but also successful strategies to avoid kleptoparasitism before carcass-based resources could become an important part of the diet. Although hominins were unlikely to have been top predators upon first entrance into the carnivore guild, effective anti-predator/anti-kleptoparasitism strategies in combination with the eventual evolution of active hunting would have increased the rank of hominin species within the guild. While the appearance of stone tools at 2.6 Ma has no apparent effect upon carnivorans, the appearance of Homo ergaster  after 1.8 Ma may have been at least partly responsible for the decrease in the carnivoran origination rate and the increase in the extinction rate at this time. The behavior of H. ergaster , climate change, and concomitant changes in prey species richness may have caused carnivoran species richness to drop precipitously after 1.5 Ma. In this situation, even effective kleptoparasitism by H. ergaster  may have been enough to drive local populations of carnivorans that overlapped with hominins in dietary resources to extinction. Possibly as a result, the modern guild, which evolved within the last few hundred thousand years, is composed primarily of generalists. Although the impact of H. sapiens on the carnivoran guild cannot be assessed due to a lack of carnivoran fossils from this time period, one might not consider the modern carnivore guild to be complete until the appearance of our species approximately 200,000 years ago.

The genus Crocuta evolved in Africa no later than 4 Ma and dispersed from that continent between 2.5 and 2 Ma. At its peak in the late Pleistocene, Crocuta had a geographic distribution that encompassed most of the Old World, except for the northernmost parts of Siberia. Herein, we describe new material of Crocuta from Africa, review the fossil record of the genus in the rest of the world, and revise its species-level taxonomy on the basis of metric and morphological data. We conclude that the genus comprises at least seven extinct species in addition to the extant C. crocuta and that the fossil record includes a number of transitional specimens that cannot be classified to species. Extinct African species are C. venustula (synonyms: C. dietrichi, C. dbaa; early Pliocene – early Pleistocene), C. ultra (early – middle Pleistocene), and C. eturono (late Pliocene). Asian species are C. honanensis (early Pleistocene) and C. ultima (middle – late Pleistocene), possibly with an unnamed species in the early Pleistocene of India and Pakistan. European species are C. intermedia (middle Pleistocene) and C. spelaea (middle – late Pleistocene).

The order Carnivora is one of the most speciose mammalian groups with over 280 living species and well over 1000 known extinct species. Here we present an overview of the evolutionary history of the carnivoran brain drawn from 150 years of palaeoneurological research. We demonstrate that the basic sulcal pattern is similar across living carnivorans, which is as follows. In lateral aspect, the cerebrum consists of convolutions arranged in concentric arcs around the Sylvian sulcus that progressively increase in length. In the dorsal aspect of most living carnivorans, a cruciate sulcus is present at the anterior part of the cerebrum. Fossils of early carnivorans display a small cerebral cortex with limited gyrification. A progressive cortical expansion and a trend towards a more complex gyral pattern can be observed. The surface area of the cerebral cortex expanded independently several times in carnivoran evolution, coinciding with increasingly more complex sulcal patterns. Differences in cortical folding patterns distinguish various families of carnivorans. Somatosensory evolution led to the enlargement and elaboration of certain cortical areas. The evolution from a basal pattern to an array of differences in folding patterns and proportional size differences between cortical areas led to the variation we see today.