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Bite force adjusted for body mass allometry (BFQ), maximal prey size and feeding category in 31 extant mammalian carnivores. (RMPS, maximal prey size (1, greater than maximal body mass of predator; 2, less than maximal body mass of predator); FC, feeding category (1, hypercarnivore; 2, other); '-', insufficient data. Maximal body mass data largely from Meers (2002). For additional data see Electronic Appendix, section A.)
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We provide the first predictions of bite force (BS) in a wide sample of living and fossil mammalian predators. To compare between taxa, we calculated an estimated bite force quotient (BFQ) as the residual of BS regressed on body mass. Estimated BS adjusted for body mass was higher for marsupials than placentals and the Tasmanian devil (Sarcophilus...
Contexts in source publication
Context 1
... although the ability to bring down large prey in canids is related to cooperative hunting, it is still reflected in a higher BFQ. Within living Felidae, BFQ values were 57 and 75 for the two species that specialize in relatively small prey, while BFQ was 94 or greater for the seven known to take relatively large prey (table 2). B S adjusted for body mass was also low in bears (44-78), which are restricted to relatively small prey (Meers 2002). ...Context 2
... BFQ was 100 or higher in 15 of the 16 extant placental and marsupial carnivores sampled that take prey larger than their own maximal body masses. In 12 of the 14 extant species where maximal prey size was less than the species' mean body mass, BFQ was less than 100 (table 2). The difference between large and small prey specialists was significant (t(28)ZK4.92, ...Context 3
... considered in isolation, B S adjusted for body mass is not an infallible predictor. In the aardwolf (Proteles cristatus), BFQ is low (77), but higher than in some bears, a viverrid and two small cat species (table 2). Although this finding is consistent in that all take relatively small prey, it does not reflect the fact that P. cristatus subsists largely on termites. ...Similar publications
In addition to biting, it has been speculated that the forces resulting from pulling on food items may also contribute to feeding success in carnivorous vertebrates. We present an in vivo analysis of both bite and pulling forces in Varanus komodoensis, the Komodo dragon, to determine how they contribute to feeding behavior. Observations of cranial...
Studies on the effect of temperature on whole-animal performance traits other than locomotion are rare. Here we investigate the effects of temperature on the performance of the turtle feeding apparatus in a defensive context. We measured bite force and the kinematics of snapping in the Common Snapping Turtle (Chelydra serpentina) over a wide range...
Five striking and prey capture events of two goblin sharks were videotaped at sea for the first time, showing their extraordinary biting process. The goblin sharks swung their lower jaw downward and backward to attain a huge gape and then rapidly protruded the jaws forward a considerable distance. The jaws were projected at a maximum velocity of 3....
Citations
... First, injuries in contests over food within a pack have never been observed (Creel & Creel, 1995. Second, the risk of injury during aggressive competitions would seem to be high, as African painted dogs possess the strongest bite forces relative to their body mass among extant carnivores (Wroe et al., 2005). Finally, given the risk of kleptoparasitism and predation, food competition appears costly (Jordan et al., 2022). ...
... In previous studies, PAB was described as an "appeasement behaviour" or "begging" in feeding contexts where both aggression and food sharing likely occur, although its role has not been examined (Estes, 1967;Rütten & Fleissner, 2004;Bucci et al., 2022;Jordan et al., 2023). In this species, severe injuries due to conflicts among group members have rarely been observed despite their strong bite force (Creel & Creel, 2002;Wroe et al., 2005). This suggests that appeasement behaviours to prevent escalated aggression should be fundamental for maintaining the peacefulness of a pack in this species. ...
In some group-living species that share food, interindividual disagreement on access to food is mediated by several types of negotiation, ranging from appeasing the current owner to reduce aggression and gain access to the food, to harassment where non-owners assert their presence and apply insistent pressure until owners give up their food. In some species, non-owners employ specific behaviours used in other social contexts during negotiation, which makes it challenging to discern their precise functions. The core prediction of the harassment hypothesis is that intense pressure by beggars makes owners abandon their food and leads to food monopolisation, which is not predicted by the appeasement hypothesis. In the African painted dog ( Lycaon pictus ), non-owners assume a low posture and produce high-pitched vocalisations — a suite of behaviours considered appeasement in non-feeding contexts. This study examined whether these behaviours, referred to collectively as putative appeasement behaviour (PAB), serve as appeasement in the context of feeding or whether they may also, or only, be used for harassment. To this end, we used behavioural experiments in captive parent–offspring or full sibling pairs. Individuals showed more frequent PAB when offered food that could not be easily shared (one vs. two bones). As aggression also only occurred under that condition, PAB seems to have a function in appeasement. However, we observed a positive effect of PAB on food monopolisation by PAB actors but not on co-feeding. Persistent PAB led to monopolisation, indicating that these behaviours serve as a form of harassment in feeding. We did not observe reciprocity between paired individuals, another possible form of food monopolisation besides appeasement and harassment. In conclusion, PAB in the African painted dog functions as both appeasement and harassment, and this highly tolerant species employs negotiation strategies in feeding.
... A representative study that estimates quantitative values of masticatory muscles from skull measurements employs a method developed by Thomason (1991). This method involves calculating the area from photographs taken of both the dorsal and ventral sides of the skull (Christiansen & Adolfssen, 2005;Christiansen & Wroe, 2007;Damasceno et al., 2013;Ellis et al., 2008;McHenry et al., 2007;Wroe, 2008;Wroe et al., 2005;Wroe & Milne, 2007;. ...
... Many research works have estimated the masticatory muscle from the skull to calculate the bite force (Dickinson et al., 2021;Ellis et al., 2008Ellis et al., , 2009Kiltie, 1984;Perry, 2018;Perry et al., 2015;Perry, Hartstone-Rose, & Logan, 2011;Thomason, 1991). Most of the bite force literature of carnivorans have utilized Thomason's method: wide array of species (Christiansen & Adolfssen, 2005;Christiansen & Wroe, 2007;Wroe et al., 2005;Wroe & Milne, 2007;, felids (Sakamoto et al., 2010), canids (Damasceno et al., 2013), and the sabertooth cat (Smilodon fatalis) . Since our method does not estimate bite force, we cannot make a side-by-side comparison with the Thomason's method (Thomason, 1991). ...
Masticatory muscles are composed of the temporalis, masseter, and pterygoid muscles in mammals. Each muscle has a different origin on the skull and insertion on the mandible; thus, all masticatory muscles contract in different directions. Collecting in vivo data and directly measuring the masticatory muscles anatomically in various Carnivora species is practically problematic. This is because some carnivorans can be ferocious, rare, or even extinct. Consequently, the most practical method to collect data on the force generated by the masticatory muscle is to estimate the force based on skulls. The physiological cross‐sectional area (PCSA) of each masticatory muscle, which correlates to the maximum force that can be produced by a muscle, was quantified. Using computed tomography, we defined the three‐dimensional measurement area for 32 carnivoran species based on the origin and insertion of masticatory muscles specified by observable crests, ridges, and scars. Subsequent allometric analysis relating the measurement area on skull surface to the PCSA for each masticatory muscle measured in fresh specimens revealed a strong correlation between the two variables. This finding indicates that within Carnivora, an estimation of absolute masticatory muscle PCSA can be derived from measurements area on skull surface. This method allows for the use of cranial specimens, housed in museums and research institutions, that lack preserved masticatory muscles in quantitative studies involving masticatory muscle PCSA. This approach facilitates comprehensive discussions on the masticatory muscle morphology of Carnivora, including rare and extinct species.
... Bite force is heritable (Anderson et al., 2008;Zablocki-Thomas et al., 2021) and is a good indicator of an animal's dietary and behavioural ecology (Aguirre et al., 2003;Herrel et al., 2001;Krishnan, 2023;Maestri et al., 2016;Nogueira et al., 2009;Sakamoto, 2021). As such, the biting capability (bite force) of an animal has been widely studied in vertebrates (Sakamoto et al., 2019), ranging from fish (e.g., Herrel et al., 2002), amphibians (e.g., Deban & Richardson, 2017), reptiles (reviewed by Deeming, 2022), birds (reviewed by Deeming et al., 2022), and mammals (Grandal-d'Anglade, 2010;Grubich et al., 2012;Holliday, 2009;Mazzetta et al., 2009;Thomason, 1991;Wroe et al., 2005). More recently, several studies have also measured mandible forces in invertebrates, such as ants (Püffel et al., 2021). ...
... Bite force is often measured in vivo with vertebrates biting down on force transducers (Ellis et al., 2008;Herrel et al., 1998;Sustaita & Hertel, 2010;Verma et al., 2017). However, in instances where this is not possible, for example, when specialised equipment is not available, or for extinct species in a palaeontological context, bite force can be inferred through the use of skeletal elements, such as skull width (Anderson et al., 2008) and skull length (Wroe et al., 2005) in mammals, or, in dinosaurs, dimensions of the cranial adductor chambers (Mazzetta et al., 2004;Rayfield et al., 2001;Sakamoto et al., 2019). Alternative methods include calculation of bite force following finite element analysis of 3D scans derived from computerised tomography (e.g., Cost et al., 2020). ...
... Physical elements of the skull allow for prediction of a functional trait, such as skull width being a reliable estimator of bite force in finches (van der Meij & Bout, 2008). Although in the fossil record soft tissues are often not preserved (Lautenschlager et al., 2013), other osteological elements, such as muscle scarring, are commonly measured as a proxy for the size of muscles (Sakamoto et al., 2019;Wroe et al., 2005). This 'dry skull method' and has been extensively used to predict bite force in extinct species, especially mammals (Huber et al., 2005;Law & Mehta, 2019;Thomason, 1991;Walmsley et al., 2013). ...
Jaw morphology and function determine the range of dietary items that an organism can consume. Bite force is a function of the force exerted by the jaw musculature and applied via the skeleton. Bite force has been studied in a wide range of taxa using various methods, including direct measurement, or calculation from skulls or jaw musculature. Data for parrots (Psittaciformes), considered to have strong bites, are rare. This study calculated bite force for a range of parrot species of differing sizes using a novel method that relied on forces calculated using the area of jaw muscles measured in situ and their masses. The values for bite force were also recorded in vivo using force transducers, allowing for a validation of the dissection‐based models. The analysis investigated allometric relationships between measures of body size and calculated bite force. Additionally, the study examined whether a measure of a muscle scar could be a useful proxy to estimate bite force in parrots. Bite force was positively allometric relative to body and skull mass, with macaws having the strongest bite recorded to date for a bird. Calculated values for bite force were not statistically different from measured values. Muscle scars from the adductor muscle attachment on the mandible can be used to accurately predict bite force in parrots. These results have implications for how parrots process hard food items and how bite forces are estimated in other taxa using morphological characteristics of the jaw musculature.
... In felids, the TMJ consists of an elongate, cylindrical condyle that fits into a correspondingly shaped glenoid fossa, while bony structures of the temporal bone greatly limit mediolateral movement, and the articular disc is extremely thin (Arzi & Staszyk, 2019). The Tasmanian Devil, which has the strongest bite force of any extant mammal relative to body size (Wroe et al., 2005), like eutherian carnivores, has well-developed preglenoid and postglenoid processes that prevent dislocation and mediolateral gliding movements of the condyle, and the lateral pterygoid muscles attached to the condyle are very poorly developed. There is no articular disc and the Tasmanian Devil TMJ appears to be principally a ginglymoid (hinge) joint (Hayashi et al., 2013). ...
The temporomandibular joint (TMJ) is a distinguishing feature of mammals, and in most mammals includes an articular disc that buffers the loads placed on it by mastication. The disc is well developed in mammals with significant lateral masticatory jaw movements but is absent in toothless mammals, including extant monotremes, although histological studies of developing monotremes have shown rudimentary discs that fail to mature. Platypus (Ornithorhynchus anatinus) grind their food between keratinous pads in the maxillae and lower jaws and are the only edentulate mammals that masticate their food. In this study, we characterize the anatomy of the TMJ of the adult platypus to see if we can reconcile the anatomy, including the absence of the articular disc, with the mandibular movements observed in video recordings. We studied the gross anatomy of the maxillofacial region and the microstructure using microcomputed tomography (micro‐CT) and histological examination. Platypuses had well‐developed masticatory muscles but lacked an articular disc between the mandibular condyle and glenoid fossa. The surface of the glenoid fossa was slightly concave than that of the condylar head was correspondingly slightly convex. The pre‐ and postglenoid processes were not well developed. Micro‐CT showed dense trabecular bone in the anterior part of the condyle, where the lateral pterygoid muscle attached. Histological analysis showed that the surfaces of the condyle and glenoid fossa consisted of dense, avascular and thickened fibrous connective tissue. In addition, well‐developed synovial folds were present. These anatomical characteristics are consistent with both anterior and lateral movements of the mandible, while the thick layer of connective tissue substitutes for a disc by absorbing the mechanical stresses associated with mastication. The failure of the disc primordium to develop cannot be attributed to a lack of muscle development, but the distribution of stresses in the toothless platypus jaw is likely to be different from those in a masticating eutherian.
... While fatal attacks are exceedingly rare and not documented in recent times in Pennsylvania, interactions may result in injuries. Black bears are found to have a bite force of up to 800 PSI [ 2]. This amount of force is more than enough to cause extensive damage to bone and surrounding structures. ...
Cerebrospinal fluid (CSF) leakage is a known sequela of open traumatic skull fractures within the pediatric traumatic brain injury population. Black bears are a known entity within the region of northeast Pennsylvania. It is plausible to have a bear–human interaction resulting in significant bodily injury. A 15-month-old male presented in May 2023 as a level 1 trauma alert for a concerning wound at the base of the skull leaking clear fluid; suspicious for CSF. As a result of this interaction, significant bodily injury can occur, such as CSF leaks and traumatic skull fractures. Living in a region within a known bear population poses a minimal risk of injury. Pediatric populations are usually at a low risk for traumatic CSF leaks. Most of the CSF leaks will resolve spontaneously, without acute surgical intervention, as was seen in our patient after a traumatic bear mauling.
... These osteological traits position the associated masticatory musculature to maximize bite force and chewing strength. Specifically, the short, wide jaws of large prey specialists facilitate greater bite forces by increasing the leverage of the masticatory musculature (Biknevicius & Ruff, 1992;Christiansen & Wroe, 2007;Slater et al., 2009;Wroe et al., 2005). Previous estimates of the bite force quotient of L. pictus revealed that it has among the greatest relative canine bite forces of extant Carnivora, falling above the regression line between predicted bite force and body mass (Wroe et al., 2005;Damasceno et al., 2013). ...
... Specifically, the short, wide jaws of large prey specialists facilitate greater bite forces by increasing the leverage of the masticatory musculature (Biknevicius & Ruff, 1992;Christiansen & Wroe, 2007;Slater et al., 2009;Wroe et al., 2005). Previous estimates of the bite force quotient of L. pictus revealed that it has among the greatest relative canine bite forces of extant Carnivora, falling above the regression line between predicted bite force and body mass (Wroe et al., 2005;Damasceno et al., 2013). The mechanical advantage of its masticatory forces is greatest at P 3 and P 4 , falling within the range of the modern bone-cracking Crocuta crocuta (Tseng & Stynder, 2011). ...
... While masticatory muscles in L. pictus may not be relatively more massive than in other taxa, their extensive bony attachments at positions of maximal mechanical advantage (Figure 1a-c) likely result in their extremely great bite forces (Damasceno et al., 2013;Wroe et al., 2005). Here, the 3D osteological models of the skull demonstrated expanded muscular attachment sites. ...
African wild dogs (Lycaon pictus) are unique among canids in their specialized hunting strategies and social organization. Unlike other, more omnivorous canids, L. pictus is a hypercarnivore that consumes almost exclusively meat, particularly prey larger than its body size, which it hunts through cooperative, exhaustive predation tactics. Its bite force is also among the highest reported for carnivorans. Here, we dissected an adult male L. pictus specimen and conducted diffusion iodine contrast‐enhanced computed tomography (diceCT) scans to evaluate and describe its masticatory and oral cavity musculature. Muscles of mastication in L. pictus are separated by deep layers of thick intermuscular fascia and deep insertions. The superficial surface of m. masseter is entirely covered by an extremely thick masseteric fascia. Deep to m. masseter pars reflexa and superficialis are additional bellies, m. masseter pars profunda and zygomaticomandibularis. Musculus temporalis in L. pictus, divides into suprazygomatic, superficial, and deep bellies separated by a deep layer of thick intermuscular fascia, and it inserts along the entire rostral margin of the mandibular ramus. Musculus digastricus appears to comprise a single, large fusiform belly which appears to receive its innervation exclusively from CN V3 (nervus mandibularis, division of nervus trigeminus). Musculus pterygoideus medialis and lateralis are each composed of a single, deep belly. However, despite its great bite force, the jaw adductor muscle mass in L. pictus is not increased for its body size over other canid taxa. This finding suggests there are other architectural adaptations to hypercarnivory beyond increased muscle volume (e.g., pennation angle, greater strength, optimization of lever arms for mechanical advantage).
... Investigations on bite force in vertebrates have aimed to identify its best anatomical estimator and to figure out the many biological aspects it might be affecting (e.g., Anderson et al., 2008;Becerra et al., 2014;Buezas et al., 2019;Christiansen & Wroe, 2007;Cox, 2017;Curtis et al., 2010;Ellis et al., 2008;Ginot et al., 2019;Herrel et al., 2002;Kim et al., 2018;Maestri et al., 2016;Mora et al., 2018;Ross et al., 2005;Wroe et al., 2005). In line with the findings reported by Álvarez and collaborators (2015) concerning skull shape variation, we argue that bite force cannot be solely explained by phylogeny, size, or ecological attributes. ...
The mammalian skull is very malleable and has notably radiated into highly diverse morphologies, fulfilling a broad range of functional needs. Although gnawingis relatively common in mammals, this behavior and its associated morphology are diagnostic features for rodents. These animals possess a very versatile and highly mechanically advantageous masticatory apparatus, which, for instance, allowed caviomorph rodents to colonize South America during the Mid-Eocene and successfully radiate in over 200 extant species throughout most continental niches. Previous work has shown that differences in bite force within caviomorphs could be better explained by changes in muscle development than in mechanical advantages (i.e., in cranial overall morphology). Considering the strong bites they apply, it is interesting to assess how the reaction forces upon the incisors (compression) and the powerful adductor musculature pulling (tension) mechanically affect the cranium, especially between species with different ecologies (e.g., chisel-tooth digging). Thus, we ran finite element analyses upon crania of the subterranean Talas' tuco-tuco Ctenomys talarum, the semi-fossorial common degu Octodon degus, and the saxicolous long-tailed chinchilla Chinchilla lanigera to simulate: (A) in vivo biting in
all species, and (B) rescaled muscle forces in non-ctenomyid rodents to match those of the tuco-tuco. Results show that the stress patterns correlate with the mechanical demands of distinctive ecologies, on in vivo-based simulations, with the subterranean tuco-tuco being the most stressed species. In contrast, when standardizing all three species (rescaled models), non-ctenomyid models exhibited a several-fold increase in stress, in both magnitude and affected areas. Detailed observations evidenced that this increase in stress was higher in lateral sections of the snout and, mainly, the zygomatic arch; between approximately 2.5–3.5 times in the common degu and 4.0–5.0 times in the long-tailed chinchilla. Yet, neither species, module, nor simulation condition presented load factor levels that
would imply structural failure by strong, incidental biting. Our results let us conclude that caviomorphs have a high baseline for mechanical strength of the cranium because of the inheritance of a very robust “rodent” model, while interspecific differences are associated with particular masticatory habits and the concomitant level of development of the adductor musculature. Especially, the masseteric and zygomaticomandibular muscles contribute to >80% of the bite force, and therefore, their contraction is responsible for the highest strains upon their origin sites, that is, the zygomatic arch and the snout. Thus, the robust crania of the subterranean and highly aggressive tuco-tucos allow them to withstand much stronger forces than degus or chinchillas, such as the ones produced by their hypertrophied jaw
adductor muscles or imparted by the soil reaction.
... Within this study, we evaluate osteological proxies of masticatory muscle FL and behavioral correlates of maximum bony gape (MBG) in Felidae. Identified trends are then applied in conjunction with previously established bite force proxies (Christiansen & Adolfssen, 2005;Christiansen & Wroe, 2007;Dickinson et al., 2021;Thomason, 1991;Wroe et al., 2005) to reconstruct bite force and gape in S. fatalis. As such, we test the hypotheses that FL can be reliably predicted from osteological length proxies and MBG scales with behaviorally produced gapes within Felidae and propose the following predictions: ...
... Prediction 5. While some literature suggests that S. fatalis has adaptations to maintain BF at increased gapes (Emerson & Radinsky, 1980;Kurtén, 1952), most literature suggests a relatively weak BF (Christiansen, 2007;Matthew, 1910;McHenry et al., 2007;Wroe et al., 2005). Predictions of BF based on cross-sectional areas estimate that S. fatalis has among the lowest relative canine BF capabilities for a large felid (Christiansen, 2007;Wroe et al., 2005); however, absolute canine BF did not differ significantly from that of large extant pantherines. ...
... While some literature suggests that S. fatalis has adaptations to maintain BF at increased gapes (Emerson & Radinsky, 1980;Kurtén, 1952), most literature suggests a relatively weak BF (Christiansen, 2007;Matthew, 1910;McHenry et al., 2007;Wroe et al., 2005). Predictions of BF based on cross-sectional areas estimate that S. fatalis has among the lowest relative canine BF capabilities for a large felid (Christiansen, 2007;Wroe et al., 2005); however, absolute canine BF did not differ significantly from that of large extant pantherines. A computer model approach using these same cross-sectional areas combined with three-dimensional leverage to estimate muscle force estimates that S. fatalis canine BF is one third that of P. leo (McHenry et al., 2007). ...
Masticatory gape and bite force are important behavioral and ecological variables. While much has been written about the highly derived masticatory anatomy of Smilodon fatalis, there remains a great deal of debate about their masticatory behaviors. To that end, we establish osteological proxies for masticatory adductor fascicle length (FL) based on extant felids and apply these along with previously validated techniques to S. fatalis to provide estimates of fascicle lengths, maximum osteological gapes, and bite force. While the best correlated FL proxies in extant felids do not predict particularly long fascicles, these proxies may be of value for less morphologically distinct felids. A slightly less well correlated proxy predicts a temporalis FL 15% longer than that of Panthera tigris. While angular maximum bony gape is significantly larger in S. fatalis than it is in extant felids, linear gape at the canine tip and carnassial notch were not significantly different from those of extant felids. Finally, we produce anatomical bite force estimates of 1283.74 N at the canine and 4671.41 N at the carnassial, which are similar in magnitude to estimates not of the largest felids but of the much smaller P. onca, with S. fatalis producing slightly less force at the canines and more at the carnassials. These estimates align with previous predictions that S. fatalis may have killed large prey with canine shearing bites produced, in part, by force contributions of the postcranial muscles.
... This is because it is impossible to compare individuals with diametrically opposed body weights, which is why the BFQ was used. As explained in Wroe et al. [21], Christiansen [15], Hartstone-Rose et al. [22], and Damasceno et al. [23], the absolute values of bite force need to be adjusted in order to enable interspecific comparisons. Analysing the selected values in relation to body weight, it can be concluded that by far the highest bite force is possessed by the domestic cat, which has 40.9 N of bite force per 1 kg of body weight, while in the lion, this value is only 16.72 N. Bite force changes in an allometric manner, adapted to the hunting behaviour of a given individual in the context of the size of potential prey and the force required to obtain it. ...
... The bite force quotient is a value calculated as a regression of the quotient of an animal's bite force divided by its body mass. The BFQ was first used by Wroe et al. in 2005 in an article [21] on extinct and living carnivorous mammals. That work compared the bite strengths, body weights, and prey sizes of carnivores. ...
... The bite force quotient is a value calculated as a regression of the quotient of an animal's bite force divided by its body mass. The BFQ was first used by Wroe et al. in 2005 in an article [21] on extinct and living carnivorous mammals. That work compared the bite strengths, body weights, and prey sizes of carnivores. ...
The aim of this study was to analyse the bite forces of seven species from three carnivore families: Canidae, Felidae, and Ursidae. The material consisted of complete, dry crania and mandibles. A total of 33 measurements were taken on each skull, mandible, temporomandibular joint, and teeth. The area of the temporalis and masseter muscles was calculated, as was the length of the arms of the forces acting on them. Based on the results, the bite force was calculated using a mathematical lever model. This study compared the estimated areas of the masticatory muscles and the bending strength of the upper canines among seven species. A strong correlation was found between cranial size and bite force. The results confirmed the hypothesis that the weight of the animal and the size of the skull have a significant effect on the bite force.
... Mammalian carnivores are an excellent model to study the relationship between form, function, and diversity as they display a wide array of morphological and dietary diversity encompassing different lifestyles 38,43-45 . Carnivores' organismal design is generally thought to reflect resource use and studies using several functional metrics have supported a correlation between diet and bite force 43,45 . The association between bite force and diet is frequently investigated because improving bite performance can allow access to novel ecological niches 43,46 . ...
... Mammalian carnivores are an excellent model to study the relationship between form, function, and diversity as they display a wide array of morphological and dietary diversity encompassing different lifestyles 38,[43][44][45] . Carnivores' organismal design is generally thought to reflect resource use and studies using several functional metrics have supported a correlation between diet and bite force 43,45 . ...
... Mammalian carnivores are an excellent model to study the relationship between form, function, and diversity as they display a wide array of morphological and dietary diversity encompassing different lifestyles 38,[43][44][45] . Carnivores' organismal design is generally thought to reflect resource use and studies using several functional metrics have supported a correlation between diet and bite force 43,45 . The association between bite force and diet is frequently investigated because improving bite performance can allow access to novel ecological niches 43,46 . ...
Functional trade-offs can affect patterns of morphological and ecological evolution as well as the magnitude of morphological changes through evolutionary time. Using morpho-functional landscape modelling on the cranium of 132 carnivore species, we focused on the macroevolutionary effects of the trade-off between bite force and bite velocity. Here, we show that rates of evolution in form (morphology) are decoupled from rates of evolution in function. Further, we found theoretical morphologies optimising for velocity to be more diverse, while a much smaller phenotypic space was occupied by shapes optimising force. This pattern of differential representation of different functions in theoretical morphological space was highly correlated with patterns of actual morphological disparity. We hypothesise that many-to-one mapping of cranium shape on function may prevent the detection of direct relationships between form and function. As comparatively only few morphologies optimise bite force, species optimising this function may be less abundant because they are less likely to evolve. This, in turn, may explain why certain clades are less variable than others. Given the ubiquity of functional trade-offs in biological systems, these patterns may be general and may help to explain the unevenness of morphological and functional diversity across the tree of life.
