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Do lions have bigger mandibles than other bigcats
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Ive read once that lions have bigger mandibular bone than other bigcats.
Is it both relatively and propotionally bigger ?? What could be the reason for bigger and stronger mandibles ? What are the advantages ? Thanks 
It is good to tag people whom you think can answer this question. In this way it will be easy for them to reach the thread becasue they will receive notification.
Are you just asking why they have the longest lower jaw bone?
Their muzzle is longer and more narrow compared to a tigers which is storter and more robust which is why their "mandible would be larger" I'm not sure what advantages they would have other than the portrayal of a "larger head" which may add to the intimidation factor. I know the most powerful bites of big cats come from the shorter, more robust rostrum region... I.e. Jaguar and tiger @peter would know best though Here are some great studies on the differences between tiger and lion mandibles and other big cats http://wildfact.com/forum/topic-cat-anatomy 
On the old AvA and other Yuku forums relating to this topic, there were similar threads related to this discussion.
Basically, a few posters postulated that the bite force of the lion is greater than that of the tiger's due to its longer and more curved mandible. But actual studies/science proved just the opposite. A shorter and more robust skull does equal a greater bite force, and tigers/jaguars do generally have the greatest pound-for-pound bite forces of all the pantherines. I wouldn't call a lion's mandible necessarily bigger, just longer. And for tigers, the mandible is a little wider at the back end. I would call it equal, in all respect. 
From Distinguishing skulls of lions (Panthera leo) and tigers (Panthera tigris) by Per Christiansen (2008), lions do have a statistically significantly longer mandible relative to skull length than at least tigers. 134 lions had an average mandible length/condylobasal skull length (CBL) ratio of 0.7426 and a 100 the tigers had a mean value of 0.6883 for this same ratio. The data I derived the comparison from is this:
 *This image is copyright of its original author The mandible/CBL ratio of modern P. leo is essentially the same as P. atrox and P. spelaea as well. From Panthera pardus (Carnivora: Felidae) by Stein and Hayssen (2010), leopard skulls have a mandible length/CBL ratio of around 0.73-0.74, essentially the same as the lion.  *This image is copyright of its original author Lastly, the jaguar seems to have the proportionately longest mandible of all the big cats. I could not find many published measurements but this sample for example shows that the jaguar has a very long mandible. Even though only basal length was given, the mandible length/basal length ratio of the jaguar 0.842. Extrapolating basal length to CBL using 1.06 as the adjustment factor (the usual ratio of CBL/basal length in most big cats I've found), at least this jaguar sample has a mandible length/CBL ratio of 0.794, the highest of the big cats.
Analyses of Linear Variables
Males and Females are statistically distinct across each of the linear variables (I-XVII), as we hypothesized (H2); males are substantially larger than females in all linear measures (Table 4). However, the sexes do not differ by either of the shape ratios. Those ratios clearly separate lions from tigers as lions have significantly longer rostra and narrower biangular widths – thus supporting H1 as well. Although the upper carnassial (P4) and premolar-molar rows in lions are only slightly longer than those of tigers (35.57 mm vs. 33.79 mm and 68.25 vs. 63.12 respectively), these differences were also highly significant. All of the statistically significant differences including these tooth lengths along with basal skull length (II), two different metrics related to jaw length (V, and X), and the aforementioned mentioned rostral lengths (I and XIV), all relate, essentially, to the lion’s overall longer muzzle while the tiger has a significantly wider rostrum (XV). (Table 4). "The first principal component is driven most substantially by the anterior-most points relative to the position of the points that lie most close to the midline of the skull in the lateral view – i.e., the position of the zygomatics and the post-orbital processes (Fig. 6). Given that this axis divides the population by species, it is not surprising that the variables that emerge describe the relatively longer muzzle of lions relative to tigers. What is somewhat contrary to what we would have predicted both the anterior-most and posterior-most points show an anterior shift from the tiger morphospace (represented in Fig. 6– by the dot) to the lion morphospace (represented by the end of the line emerging from the dot). Thus the longer rostra found in lions is driven not by an elongation of the anterior portion of the skull, but by the relatively posterior position of the zygomatics and orbits. In other words, according to this analysis, tigers do not have relatively shorter snouts, but relatively rostral eyes and cheeks" http://caravel.sc.edu/2014/12/the-crania...ve-felids/ "RESULTS Graphing the PCA showed that species was the first principle component, accounting for 21.28% of the variation, and visibly separating the groups into lions and tigers with almost zero overlap on the x-axis (See Figure 1 & Table 2). The second principle component clearly represented captivity status, accounting for 15.58% of the variance, and separating the wild and captive specimens across the y-axis. The third principle component represented the sex of the individuals, accounting for 7.97% of the variance. Figure 2 shows the second principle component, captivity status, plotted against the third, with females occupying mostly the lower extreme of the y-axis and males occupying the higher extreme. Differences in morphology were evident at each extreme of the x-axis and y-axis of each PCA test (See Fig. 1 & 2). Among some of the differences were the length of the rostrum, mandibular angle, flexion of the mandibular angles relative to the mandibular symphysis, and the width of the skull. Rostral length differed across species, as tigers were shown to have shorter rostra than lions, which is a trait that has been described by Sunquist (2002) and Christiansen (2007). Christiansen also describes increased nasal height in tigers and differentiates between canine heights across lions and tigers. Mandibular angles also varied across the species, as tigers showed mandibles wider at the top (i.e., bi-coronal breadth) and lions showed the widest point at the base of the mandible (i.e., bi-angular breadth). Different skull shapes and differences in width were also observable across captivity status. Mandibular angle and rostrum length varied across lion and tiger individuals (Figure 1). Relative to weight, it’s the jaguar. Recent research by Adam Hartstone-Rose and colleagues at the University of South Carolina, who compared the bite forces of nine different cat species, reveals that jaguars have three-quarters the bite force of tigers. However, given that jaguars are considerably smaller (the body mass of the individual in the study was only half that of the tiger), relatively speaking their bite is stronger. “If you had to choose, you’d want to be bitten by a jaguar, not a lion or a tiger. But pound for pound, jaguars pack a stronger punch,” says Adam. “The strength of the jaguar’s bite is due to the arrangement of its jaw muscles, which, relative to weight, are slightly stronger than those of other cats. In addition – also relative to weight – its jaws are slightly shorter, which increases the leverage for biting.” http://www.discoverwildlife.com/animals/...ngest-bite I'd be curious to see what the Jaguars jaw length is compared to lion or tigers... Statistically But it will always come down to the muscles attached (sagital crest area, masseter and temporalis) that will determine power, but usually the stouter mandible is the stronger bite, relatively speaking. A good example would be comparing a Hyena to a Wolf  *This image is copyright of its original author
Craniomandibular morphology and phylogenetic affinities of Panthera atrox: implications for the evolution and paleobiology of the lion lineage
ABSTRACT The great North American Pleistocene pantherine felid Panthera atrox has had a turbulent phylogenetic history, and has been claimed to show affinities to both the jaguar and the tiger; currently, it is most often regarded as a subspecies of the extant lion. The cranial, mandibular, and dental morphology of Panthera atrox was compared with those of extant lions, jaguars, and tigers using bivariate, multivariate, and shape analyses. Results indicate that the skull of Panthera atrox shows lion affinities, but also deviates from lions in numerous aspects. Mandibular morphology is more similar to jaguars and tigers and, as with cranial morphology, the mandible shows a number of traits not present among extant pantherines. Multivariate analyses grouped Panthera atrox separately from other pantherines. Panthera atrox was no lion, and cannot be assigned to any of the extant pantherines; it constituted a separate species. A possible scenario for evolution of P. atrox is that it formed part of a pantherine lineage that entered the Americas in the mid-Pleistocene and gave rise to the extant jaguar and Panthera atrox in the late Pleistocene of North America. These studies suggest that previous models of lion biogeography are incorrect, and although lions may have been present in Beringia, they did not penetrate into the American mainland. http://www.tandfonline.com/doi/abs/10.1671/039.029.0314 As noted above, the nasals project well posterior to the maxilla-frontal suture, another characteristic tiger trait [12], [33], [34], which is absent in P. palaeosinensis, where they are approximately at level with each other. The zygomatic arches are massive, and zygomatic height at the postorbital process is 14.3% of CBL; this is at the upper range of tigers (0.095–0.146) and P. spelaea (0.114–0.149); and it is higher than in jaguars (0.077–0.117), leopards (0.093–0.127), lions (0.098–0.137), P. palaeosinensis (0.124), and P. atrox (0.099–0.121), giving P. zdanskyi a massive cheek region, indicative of high bite forces (Supporting Information Fig. S3). Mandibular morphology is similar to that of tigers in its straight ventral profile, and the mandible is heavily built. Mandible heights at four designated points (posterior to M1; at M1/P4; at P4/P3; anterior to P3) relative to mandible length are at the upper ranges of the corresponding ratios among other species of Panthera. It is traditionally considered that primitive tigers had proportionally smaller carnassials (P4 and M1) than those of modern tigers, and that tigers with relatively large carnassials first appear on the Asian mainland at Zhoukoudian in the Late Pleistocene [4], [15], [35], but P. zdanskyi demonstrates that this is incorrect. P4 length is 13.4% of CBL; this is at the upper range of the variation among tigers (0.104–0.141), jaguars (0.105–0.137), leopards (0.113–0.141), lions (0.111–0.142), and P. spelaea (0.102–0.137); and is higher than in P. atrox (0.106–0.125). M1 is 14.7% of mandible length, which is higher than among other species of Panthera. The relative sizes of P3, P4 and P3 are also at the upper end or even above the size ranges of those of other Panthera species, demonstrating that P. zdanskyi has very large teeth. http://journals.plos.org/plosone/article...ne.0025483 @tigerluver Here is the google search, there are quite a bit of studies to go through, very, very interesting. https://scholar.google.com/scholar?q=jag...0QgQMIGjAA
Identification of Mid-Sized Cat Skulls
https://www.fws.gov/lab/idnotes/IDG7_CatSkulls.pdf Does anyone have access to this study? Mandibular force profiles of extant carnivorans and implications for the feeding behaviour of extinct predators http://onlinelibrary.wiley.com/doi/10.10...0/abstract
3 male Jaguar Mandible Sizes here @tigerluver pg. 148
https://books.google.com/books?id=Z_5AAQ...rs&f=false 178,179,182 Greatest mandible length 90,93,90 Greatest mandible height |
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