Mammalian Carnivora Research Articles

Reliable biogeography requires fossils: insights from a new species-level phylogeny of extinct and living carnivores.

A central objective of historical biogeography is to understand where clades originated and how they moved across space and over time. However, given the dynamic history of ecosystem changes in response to climate change and geological events, the manifold long-distance dispersals over evolutionary timescales, and regional and global extinctions, it remains uncertain how reliable inferences based solely on extant taxa can be achieved. Using a novel species-level phylogeny of all known extant and extinct species of the mammalian order Carnivora and related extinct groups, we show that far more precise and accurate ancestral areas can be estimated by fully integrating extinct species into the analyses, rather than solely relying on extant species or identifying ancestral areas only based on the geography of the oldest fossils. Through a series of simulations, we further show that this conclusion is robust under realistic scenarios in which the unknown extinct taxa represent a biased subset of all extinct species. Our results highlight the importance of integrating fossil taxa into a phylogenetic framework to further improve our understanding of historical biogeography and reveal the dynamic dispersal and diversification history of carnivores.

The shape of water: adaptations of cochlea morphology in seals and otters

Abstract Seals (Pinnipedia) and otters (Lutrinae) are two major taxa of the mammalian order Carnivora that independently adapted to a semi-aquatic lifestyle. Their sensory capabilities, including hearing, are still not fully understood. Notably, the functional morphology of amphibious hearing presents an interesting example for studying convergent evolution. We therefore investigated the shape and dimensions of morphological traits of the inner ear and the surrounding structures involved in sound perception using Micro-Computer Tomography (µCT) data of 52 skulls belonging to 38 species of the carnivoran subgroup Caniformia. Principal component analysis (PCA) of cochlea shape variables revealed that 82% of shape variation is explained by PC1 and PC2. A number of traits (e.g. cochlea shape, reduction in cochlea turns, flattening of the cochlea, relative size of tympanum and round window) are significantly different from terrestrial Caniformia. We also found an external cochlea foramen in all Pinnipedia, which is likely related to coping with pressure compensation during diving. Finally, we demonstrate that hearing parameters, such as characteristic hearing frequency, correlate with changes in the morphological traits that separate seals and otters from other Caniformia. Our data suggest that large parts of the morphology of ear region of these semi-aquatic carnivorans have independently adapted to allow hearing in air and water.

Correlated evolution of craniodental morphology and feeding ecology in carnivorans: a comparative analysis of jaw lever arms at tooth positions

AbstractSpecies in the mammalian order Carnivora have extremely diverse diets. The association between diet and craniodental morphology in carnivorans has been the subject of a number of studies. The distance from the jaw joint to the tooth positions may contribute to the ability to acquire and process food because it corresponds to the outlever arm when the jaw functions as a lever to generate a bite force. A shorter outlever arm relative to the inlever arm of the masticatory muscle generates a higher bite force. This study measured the distances from the jaw joint to different points of the teeth as the outlever lengths in the crania of terrestrial Carnivora species to show that outlever lengths corrected for phylogeny and a measure of the inlever length differ according to dietary habits among carnivorans. The distance from the jaw joint to the last molar was shortest in folivores, followed by aquatic prey specialists, suggesting that consumption of tough plant materials and, to some extent, aquatic prey with hard exoskeletons has favoured the evolution of a shorter outlever to allow stronger bites with enlarged molars. In contrast, among Canidae species, a shorter outlever to canines was associated with feeding on large prey, but this association was not found across carnivorans, suggesting that the correlated evolution of a shorter outlever at the canines and specialization for feeding on large prey depends on foraging and hunting behaviours. Combined, these findings provide some evidence that distances from the jaw joint to different points of the teeth are adapted to different feeding ecologies in carnivorans.

Frugivory and Seed Dispersal by Carnivorans

Seed dispersal is critical to the ecological performance of sexually reproducing plant species and the communities that they form. The Mammalian order Carnivora provide valuable and effective seed dispersal services but tend to be overlooked in much of the seed dispersal literature. Here we review the literature on the role of Carnivorans in seed dispersal, with a literature search in the Scopus reference database. Overall, we found that Carnivorans are prolific seed dispersers. Carnivorans’ diverse and plastic diets allow them to consume large volumes of over a hundred families of fruit and disperse large quantities of seeds across landscapes. Gut passage by these taxa generally has a neutral effect on seed viability. While the overall effect of Carnivorans on seed dispersal quality is complex, Carnivorans likely increase long-distance dispersal services that may aid the ability of some plant species to persist in the face of climate change.

Palaeoecological significance of the “wolf event” as revealed by skull ecometrics of the canid guilds

Members of the mammalian order Carnivora are rarely considered as proxies for palaeoecological reconstructions due to their broad phenotypic plasticity and high climatic tolerance. However, palaeontologists have traditionally interpreted the appearance of some particular carnivoran species in relation to major climatic events. The ‘wolf event’ characterised the inset of climatic deterioration for continental Eurasian fauna, ca 2.0 million years ago. It was defined as the dispersal of cursorial wild canids from East Asia to Europe consequently to the spread of the steppe environment. Anecdotal interpretations were never supported by rigorous testing about the palaeoecological significance of these canid taxa. Here, we employ two dimensional geometric morphometrics of canid skulls to characterise and interpret the structure of extant guilds and its relationship with climate and provide inferences on the early Pleistocene Valdarno community. Averaged skull size and shape of canid guilds are currently associated with climatic parameters that reflect annual mean temperature, seasonality and precipitation. The canid guild from Valdarno showed a clustered phylogenetic structure and its average shape resembles those of communities characterised by relatively high seasonal environments. This study supports the use of canid community structure for palaeoclimatic reconstructions and validate the early Pleistocene as a period of climatic deterioration for Eurasian large mammal fauna.

Parental Behavior in Carnivores.

The mammalian order Carnivora is generally defined as species that feed exclusively or to some degree by eating other animals. The Carnivora comprise around 280 species, divided into 16 families, 13 of which are terrestrial and 3 aquatic. Carnivores are spread across the entire planet, including the two polar regions and on land and sea. Consistent with such diverse ecologies, there is no typical pattern of parental care distinguishing carnivores from other mammals. Using examples from different taxonomic families, our aim is to illustrate the diversity of parental care in Carnivora. Major topics include parental care before and after birth of the young, paternal, and alloparental care and the process of weaning. Given the position of many carnivores at the apex of food chains, a greater understanding of their patterns of parental care as a vital part of reproductive biology is essential to conservation programs.

Influence of phylogeny on the estimation of diet from dental morphology in the Carnivora

AbstractBecause teeth are the most easily preserved part of the vertebrate skeleton and are particularly morphologically variable in mammals, studies of fossil mammals rely heavily on dental morphology. Dental morphology is used both for systematics and phylogeny as well as for inferences about paleoecology, diet in particular. We analyze the influence of evolutionary history on our ability to reconstruct diet from dental morphology in the mammalian order Carnivora, and we find that much of our understanding of diet in carnivorans is dependent on the phylogenetic constraints on diet in this clade. Substantial error in estimating diet from dental morphology is present regardless of the morphological data used to make the inference, although more extensive morphological datasets are more accurate in predicting diet than more limited character sets. Unfortunately, including phylogeny in making dietary inferences actually decreases the accuracy of these predictions, showing that dietary predictions from morphology are substantially dependent on the evolutionary constraints on carnivore diet and tooth shape. The “evolutionary ratchet” that drives lineages of carnivorans to evolve greater degrees of hypercarnivory through time actually plays a role in allowing dietary inference from tooth shape, but consequently requires caution in interpreting dietary inference from the teeth fossil carnivores. These difficulties are another reminder of the differences in evolutionary tempo and mode between morphology and ecology.

Macroevolutionary ecomorphology of the Carnivora skull: adaptations and constraints in the extant species

Abstract The mammalian order Carnivora is characterized by a broad taxonomic and ecological diversity. By using a large sample of extant species, we tested the impact of ecological factors on carnivoran skull (cranium and mandible) morphology, taking advantage of a combined geometric morphometrics and comparative method approach. We implemented several evolutionary models to account for different tempo and mode of evolution in size and shape data. These models validated the association between skull morphology and diet at the interspecific scale. The functional distinction between pinniped (aquatic) and fissiped (mostly terrestrial) taxa was found valid only in mandible shape and cranial size. High levels of morphological disparity and evolutionary rates were identified in specialized dietary groups, and positive association between rates and disparity was found for skull size. Cranium and mandible showed consistent patterns of covariation that reflect constrained functional processes, which stabilize the ecomorphological evolution of Carnivora. Aquatic adaptations allowed carnivorans to invade and persist within novel regions of the mandibular morphospace. This ecological shift did not increase morphological disparity but occurred at a faster rate than in terrestrial species. Those species exhibit a stronger level of cranio-mandibular covariation due to constraints imposed by more demanding masticatory adaptations.

Mice and Habitat Complexity Attract Carnivorans to Recently Burnt Forests

Faunal responses to wildfire depend on the fire effects on direct mortality, habitat structure, and resource availability for animals. Despite the importance of large predators in terrestrial trophic webs, little is still known about how fire affects carnivorans (the mammalian order Carnivora). To evaluate the responses of the carnivoran community to fire, we studied three recently burnt forest areas in the western Mediterranean basin. Line transects were used to quantify evidence of carnivorans (mainly feces) and to measure environmental variables and resources (small mammal abundance, fleshy fruit availability, and plant cover). Throughout the study, we found 212 carnivoran field signs, 93% of them produced by red fox and stone marten. Immediately after fire, carnivoran occurrence was more frequent close to the perimeter of the burnt area, where fire severity was low, and in places with greater small mammal abundance. Small mammal abundance and plant cover had the greatest effect on the frequency of occurrence of red fox in the burnt area surroundings, and this increased with time-since-fire in the burnt area. Furthermore, the presence of red fox did not affect stone marten occurrence. Stone martens were found around the burnt area perimeter, probably because of their preference for high plant cover, and they were not significantly affected by small mammal abundance. The scat frequency of occurrence of both species was not significantly related to fleshy fruit availability. Accordingly, rodents and carnivorans were more abundant where the habitat was more complex. Our results show that the responses of some carnivorans to fire are influenced, directly and indirectly, by habitat structure and resource availability.

Morphological evolution of the carnivoran sacrum.

The sacrum is a key piece of the vertebrate skeleton, since it connects the caudal region with the presacral region of the vertebral column and the hind limbs through the pelvis. Therefore, understanding its form and function is of great relevance in vertebrate ecomorphology. However, it is striking that morphometric studies that quantify its morphological evolution in relation to function are scarce. The main goal of this study is to investigate the morphological evolution of the sacrum in relation to its function in the mammalian order Carnivora, using three-dimensional (3D) geometric morphometrics. Principal component analysis under a phylogenetic background indicated that changes in sacrum morphology are mainly focused on the joint areas where it articulates with other parts of the skeleton allowing resistance to stress at these joints caused by increasing muscle loadings. In addition, we demonstrated that sacrum morphology is related to both the length of the tail relativised to the length of the body, and the length of the body relativised to body mass. We conclude that the sacrum in carnivores has evolved in response to the locomotor requirements of the species analysed, but in locomotion, each family has followed alternative morphological solutions to address the same functional demands.

Bacteria isolated from Bengal cat (Felis catus × Prionailurus bengalensis) anal sac secretions produce volatile compounds potentially associated with animal signaling.

In social animals, scent secretions and marking behaviors play critical roles in communication, including intraspecific signals, such as identifying individuals and group membership, as well as interspecific signaling. Anal sacs are an important odor producing organ found across the carnivorans (species in the mammalian Order Carnivora). Secretions from the anal sac may be used as chemical signals by animals for behaviors ranging from defense to species recognition to signaling reproductive status. In addition, a recent study suggests that domestic cats utilize short-chain free fatty acids in anal sac secretions for individual recognition. The fermentation hypothesis is the idea that symbiotic microorganisms living in association with animals contribute to odor profiles used in chemical communication and that variation in these chemical signals reflects variation in the microbial community. Here we examine the fermentation hypothesis by characterizing volatile organic compounds (VOC) and bacteria isolated from anal sac secretions collected from a male Bengal cat (Felis catus × Prionailurus bengalensis), a cross between the domestic cat and the leopard cat. Both left and right anal sacs of a male Bengal cat were manually expressed (emptied) and collected. Half of the material was used to culture bacteria or to extract bacterial DNA and the other half was used for VOC analysis. DNA was extracted from the anal sac secretions and used for a 16S rRNA gene PCR amplification and sequencing based characterization of the microbial community. Additionally, some of the material was plated out in order to isolate bacterial colonies. Three taxa (Bacteroides fragilis, Tessaracoccus, and Finegoldia magna) were relatively abundant in the 16S rRNA gene sequence data and also isolated by culturing. Using Solid Phase Microextraction (SPME) gas chromatography-mass spectrometry (GC-MS), we tentatively identified 52 compounds from the Bengal cat anal sac secretions and 67 compounds from cultures of the three bacterial isolates chosen for further analysis. Among 67 compounds tentatively identified from bacterial isolates, 51 were also found in the anal sac secretion. We show that the bacterial community in the anal sac consists primarily of only a few abundant taxa and that isolates of these taxa produce numerous volatiles that are found in the combined anal sac volatile profile. Several of these volatiles are found in anal sac secretions from other carnivorans, and are also associated with known bacterial biosynthesis pathways. This is consistent with the fermentation hypothesis and the possibility that the anal sac is maintained at least in part to house bacteria that produce volatiles for the host.

Hierarchy in adaptive radiation: A case study using the Carnivora (Mammalia).

Simpson's "early burst" model of adaptive radiation was intended to explain the early proliferation of morphological and functional variation in diversifying clades. Yet, despite much empirical testing, questions remain regarding its frequency across the tree of life. Here, we evaluate the support for an early burst model of adaptive radiation in 14 ecomorphological traits plus body mass for the extant mammalian order Carnivora and its constituent families. We find strong support for early bursts of dental evolution, suggesting a classic Simpsonian adaptive radiation along dietary resource axes. However, the signal of this early burst is not consistently recovered in analyses at the family level, where support for a variety of different models emerges. Furthermore, we find no evidence for early burst-like dynamics in size-related traits, and Bayesian analyses of evolutionary correlations corroborate a decoupling of size and dental evolution, driven in part by dietary specialization. Our results are consistent with the perspective that trait diversification unfolds hierarchically, with early bursts restricted to traits associated with higher level niches, such as macrohabitat use or dietary strategy, and thus with the origins of higher taxa. The lack of support for early burst adaptive radiation in previous phylogenetic studies may be a consequence of focusing on low-level niche traits (i.e., those associated with microhabitat use) in clades at shallow phylogenetic levels. A richer understanding of early burst adaptive radiation will require a renewed focus on functional traits and their evolution over higher levelclades.

Biomechanical simulations of Leptarctus primus (Leptarctinae, Carnivora), and new evidence for a badger-like feeding capability

ABSTRACTVariations in craniodental morphology have been correlated to feeding adaptations in living organisms and used as proxies for paleodiet reconstruction. Within the mammalian order Carnivora, the Miocene fossil musteloid Leptarctus has been variably interpreted as a carnivore, frugivore, herbivore, omnivore, or insectivore based on morphological comparisons with extant species. Here, we perform the first simulation of cranial biomechanics in Leptarctus primus, aiming to identify a living analogue using biomechanical capability rather than qualitative morphology. Finite element models (FEMs) of 18 extant carnivorans and two extinct outgroup taxa were used to compare known diet-biomechanics relationships with the biomechanical properties of L. primus FEMs within a phylogenetic context. Multivariate analyses of simulated bite efficiency and skull stiffness values indicate that L. primus is most similar overall to Taxidea taxus (American badger) in unilateral bite simulations. Based on biomechanical predictions, we postulate that L. primus resembled the American badger in its feeding ecology more closely than any other taxon tested and thus conclude that L. primus was dominantly a carnivore with an auxiliary feeding capability of omnivory. We also compared the L. primus FEMs with the potentially synonymous Hypsoparia bozemanensis to determine a possible range of feeding capabilities. We observed an increase in mechanical efficiency with a deepening of the zygomae of H. bozemanensis, a trait previously used to differentiate it from L. primus. Ongoing work to expand the database of cranial biomechanical simulation data across Carnivoramorpha should help to further clarify evolutionary patterns of skull biomechanical specializations in musteloids and other carnivorans.

Large species within carnivora are large carnivores.

Wolf & Ripple [1] is a global study that explored the potential for large carnivore reintroductions, identifying protected areas and other regions with low human footprint that warrant further investigation as possible locations for rewilding. In his comment, Miranda [2] raised a number of points related to Wolf & Ripple [1]. His primary points are that Wolf and Ripple (i) used terminology (carnivore, apex predator, and guild) incorrectly, (ii) selected an inappropriate group of species to study and (iii) listed some unsuitable sites for large carnivore reintroductions. However, each of these criticisms is fundamentally flawed and only acts to hinder conservation efforts. Miranda stated that the species selected by Wolf and Ripple ‘were neither necessarily apex predators nor carnivores, but a subset of the mammalian order Carnivora, […]'. However, Wolf and Ripple did not claim that the species being studied are apex predators. In fact, the term ‘apex predator' does not appear anywhere in the main text or supplement of Wolf and Ripple. The species selected included 25 large carnivore species with a body mass greater than or equal to 15 kg that have relatively accurate historic and current range maps. The scope and purpose of Wolf and Ripple was to identify potential reintroduction sites for large-bodied members of order Carnivora without regard for whether each individual species was an apex predator, which is in itself context dependent. For example, coyotes ( Canis latrans ) may be considered mesopredators when wolves are present, but apex predators when wolves are absent [3]. Had Wolf and Ripple focused on potential reintroductions of a different taxonomic order, such as Primates, would Miranda then critique that the paper did not focus enough on other groups of vertebrates? Miranda is incorrect in his claim that the species selected are …

Reintroducing apex predators: the perils of muddling guilds and taxocenoses.

Wolf & Ripple [1] make the case for ‘large carnivore' conservation through reintroductions. The selected species, however, were neither necessarily apex predators nor carnivores, but a subset of the mammalian order Carnivora, including those ranging from insectivores–omnivores (sloth bear, Melursus ursinus [2,3]; sun bear, Helarctos malayanus [4]) to herbivores–omnivores (Andean bear, Tremarctos ornatus [3,5]; American black bear, Ursus americanus [6]), full omnivores (Asiatic black bear, Ursus thibetanus [7,8]; brown bear, Ursus arctos [9,10]) and several hypercarnivores (jaguar, Panthera onca [11]; dhole, Cuon alpinus [12]; cheetah, Acinonyx jubatus [13]). At first, Wolf & Ripple lump together mammalian carnivores (those in the order Carnivora, which may or may not be regular predators), apex predators (which occupy the top of food chains [14]) and any carnivore (which primarily consumes other vertebrates). Further, they mixed guilds (a group of species that exploit similar resources) with taxocenosis (a group of sympatric species sharing a common phylogenetic clade). Consequently, the authors provide a biased assessment of reintroduction priorities based on conservation imperatives that are not restricted to any of these groups, but primarily associated with apex predators. This commentary explores the development of this muddle, which I interpret to be mainly due to a combination of inaccurate use of nomenclature and concepts. Furthermore, the authors make some mistakes for a number of proposed reintroduction sites that proper investigation would have revealed to be inappropriate. Mammalian carnivores are not alone as apex predators, as the latter comprise a diverse set of terrestrial and aquatic vertebrates on Earth [14], which include (but are not limited to) large raptors and large, predatory reptiles. By equating apex predators …

Physiological mechanisms mediating patterns of reproductive suppression and alloparental care in cooperatively breeding carnivores

Although cooperation represents a long-standing evolutionary puzzle, field studies on social carnivores have contributed greatly to our understanding of the selective forces favoring cooperative breeding. Despite these insights, our grasp of the proximate mechanisms facilitating cooperation in carnivores remains surprisingly limited. Here we provide an overview of our current knowledge of the endocrine mechanisms mediating cooperative breeding in terrestrial species belonging to the mammalian order Carnivora. We focus primarily on aspects of reproductive suppression and alloparental care. We find few studies on the topic, with some of the best studies focusing on the behavioral endocrinology of cooperative breeding in canids (dogs) and herpestids (mongooses). Overall, these studies suggest that breeding females typically have higher circulating levels of estrogen, luteinizing hormone, progesterone, and prolactin than do non-breeding adult females. We also find that among males, testosterone levels are often elevated in breeders compared to non-breeding adult males. The effect of glucocorticoids on reproductive suppression in carnivores appears to be sex-specific: breeding males typically have higher glucocorticoid levels than their non-breeding subordinates, but there is no clear pattern for breeding females. Finally, elevated levels of prolactin and oxytocin are consistently associated with alloparental care in cooperatively breeding carnivores, whereas testosterone and glucocorticoids are often lower in individuals who participate in alloparenting. Taken together, our synthesis elucidates striking gaps in our knowledge of carnivore physiology, especially the endocrine mechanisms promoting alloparental care, and we identify important areas for future research.

The role of exotic mammals in the diet of native carnivores from South America

AbstractA better understanding of the effects of exotic species is fundamental for ecosystem management, given that biological invasions are major agents of change affecting native biodiversity worldwide. However, exotic species can also have positive effects on native communities, for instance by providing additional food sources.We reviewed dietary studies in the scientific literature published between 1980 and 2016 in order to examine the role of exotic mammals in the diets of 42 terrestrial species of the mammalian order Carnivora from South America. We recorded information about species' characteristics and analysed the ways in which they relate to exotic mammal consumption.We found 62 references in which 11 carnivores from four families were reported to consume exotic mammals. Using only dietary studies in which the frequency of occurrence of each prey item was presented, we compiled 152 cases from 56 papers.The frequency of occurrence of exotic mammals in the diet of South American carnivores reached on average 21%. The more common prey–carnivore interactions occurred with exotic lagomorphs, while exotic ungulates were less frequently consumed and were only preyed upon by pumasPuma concolor. Consumers with mainly carnivorous habits consumed exotic mammals more frequently than frugivorous or omnivorous species.The carnivore species and the location of the study area influenced the frequency of occurrence of exotic mammals in the diets described. Certain carnivores, including the puma, culpeo foxLycalopex culpaeus, Pampas foxLycalopex gimnocercus, lesser grisonGalictis cujaand Molina's hog‐nosed skunkConepatus chinga, consumed more exotic mammals than average, and the occurrence of exotic mammals was the highest in the diets of carnivores in the southwestern regions of South America.Exotic mammals in South America can create new food web interactions in the native carnivore community and can serve as an important food resource for some native species. This is particularly true in human‐transformed landscapes, where native prey populations have declined. Thus, it is important to consider the role of exotic mammals in the conservation of native carnivore populations.

Insights from long‐term field studies of mammalian carnivores

Most carnivorans (members of the mammalian order Carnivora) are elusive and long lived, so long-term studies are required to understand their basic biology and, ultimately, to conserve them. Here, we review examples of the wealth of information about the social systems, ecophysiology, and ecology of gregarious, terrestrial, carnivorous carnivorans (hereafter, carnivores) generated by long-term field studies of free-living, individually recognizable carnivores. Our synthesis yields key insights about the evolutionary forces favoring cooperation and ecological forces shaping social dynamics. The genetic assignment of parentage permits elucidation of the extent of reproductive skew in natural populations spanning multiple generations. Tracking of individuals across their life spans reveals underlying physiological, behavioral, and ecological mechanisms mediating reproductive suppression and dispersal. Long-term studies permit a comprehensive understanding of the ways in which intrinsic and extrinsic factors, including conflict with humans, regulate carnivore populations. Long-term studies also provide crucial baseline information required for the conservation of carnivores in the face of burgeoning human populations and global climate change. Notably, many conservation problems unfold on timescales only addressable with long-term data. Although we have yet to exploit the full wealth of information from long-term field studies, these valuable repositories have already yielded myriad insights about mammalian carnivores that would be unobtainable from studies conducted over shorter timescales.

Diversification histories for North American and Eurasian carnivorans

The evolutionary processes that formed present-day biological diversity can be inferred through modelling past rates of extinction and origination from observations in the fossil record. We analyzed observations of over 5800 records from North America and Eurasia for 972 species in the mammalian order Carnivora. Using these records of carnivoran fossils, we estimated extinction, speciation and net diversification, while simultaneously estimating sampling probability, for the past 28 Myr. While global carnivoran diversification through the Neogene showed a pattern of surprisingly stability, diversification dynamics differ considerably between North America and Eurasia. This is particularly evident in the interval from 9 to 8 Mya, in which there is a pronounced peak of positive diversification in Eurasia that is not observed in the North American record, and from 6 to 5 Mya, in which North America experienced high rates of positive diversification, while Eurasia experienced significantly negative diversification. Our results indicate that North American members of the dogs, bears and amphicyonids, as well as other basal members of the Caniformia have lower rates of average net diversification than their counterparts in Eurasia, due to lower rates of speciation. However, average rates net diversification and their components are not distinguishable among other subclades of carnivorans in the on the two continents. In fact, most carnivoran subclades do not have significantly different estimates of average net rates of diversification.

Ecomorphology of Carnivora challenges convergent evolution

Convergent evolution is often reported in the mammalian order Carnivora. Their adaptations to particularly demanding feeding habits such as hypercarnivory and durophagy (consumption of tough food) appear to favour morphological similarities between distantly related species, especially in the skull. However, phylogenetic effect in phenotypic data might obscure such a pattern. We first validated the hypotheses that extant hypercarnivorous and durophagous large carnivorans converge in mandibular shape and form (size and shape). Hypercarnivores generally exhibit smaller volumes of the multidimensional shape and form space than their sister taxa, but this pattern is significantly different from random expectation only when hunting behaviour categorisations are taken into account. Durophages share areas of the morphospace, but this seems to be due to factors of contingency. Carnivorans that hunt in pack exhibit incomplete convergence while even stronger similarities occur in the mandible shape of solitary hunters due to the high functional demands in killing the prey. We identified a stronger phylogenetic signal in mandibular shape than in size. The quantification of evolutionary rates of changes suggests that mandible shape of solitary hunters evolved slowly when compared with other carnivorans. These results consistently indicate that the need for a strong bite force and robust mandible override sheer phylogenetic effect in solitary hunters.