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Can someone explain this..
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The densest big cat canine tooth i've ever seen was 52.6 grams at 9.9 cm, then followed by the 168.3 grams subfossil at 15.5 cm.
BTW, the canine density does not represent the overall bone density. 
While I too noticed that Panthera leo usually has slightly longer and wider bones than Panthera tigris, I do not agree on the statement that bone density is higher in the latter then in the former. It is also not clear what it is meant by bone density. Generally density of bones are compared from the ratio of their wet mass to their wet volume measured while fully submerged in water for at least 15 minutes. Bone density can also be ascertained by their mechanical properties and by the bone mineral composition. In a study I did long time ago on skeletal properties of carnivore limb long bones, I concluded that Panthera leo appears to have slightly higher either cortical area and principal moments of inertia then Panthera tigris. This is compatible with the higher bone stresses occurring in fast locomotion of a more cursorial species. Therefore lion bones appear to likely be more then just slightly more robust as the higher external robustness in all compartments (proximal and distal epiphysis and diaphysis) is also corroborated internally.
An investigation performed in the past also revealed the ratio of the skeletal mass to total body mass computed for an adult captive female lion in excellent condition to be around 12,5 %. The ratio between musculature and total lean body mass (bones and muscles), the way it is normally computed, for the aforementioned female lion was 62.5% (59.2% if computed on total mass including fat) This value is higher then in any other mammal species on which I am aware of all the dissection details and how it has been calculated, but among these species Panthera tigris is not included. I would also expect the value higher for a wild specimen in comparable excellent physical condition. A sub-adult captive male lion evaluated as rachitic and below average size has been measured having a muscle mass percentage of 55.0% after dissection, still a value higher then the one of very most mammals. Typical range of musculature over total body mass in felids is 56-59 % and in mammals 44-50 %. Therefore Panthera leo lies very much in the upper end of felid range. I already reported in my previous post just issued on a different thread (today I am unusually productive for the Forum) that in one of my past studies I computed the lumbar vertebral column section to the presacral vertebral column length in Panthera tigris to be 33,8% on average. I computed that same ratio in Panthera leo at 32,7%. Cervical area of tigers is also proportionally slightly shorter then in lions on average (ca. 25.5 % vs 25.9%). The thoracic section averages longer in Panthera leo then in Panthera tigris (less then 41,4 % vs 40,7 %). I computed an average scapula ratio to the presacral vertebral column in Panthera leo at 24,42 % and 23,25 % in Panthera tigris, but the grestest length of processus articularis appears to be slightly longer in the tiger then in the lion (24,7 % vs 23,6 %). The brachial index in lions is higher then in tigers while the crural index is pretty much the same. Tigers appear to have proportionally longer hind limbs to fore limbs then lions. The relative length of the oleocranon process in Panthera leo is longer implying higher leverage for the triceps. The front paw is proportionally wider in the tiger, but because the lion on average has longer metacarpals (and metatarsals) in absolute terms. I can carry very much on highlighting skeletal differences, although always marginal or very marginal, but I stop here. We also know Indian and Amur tigers to have slightly longer head-and-body length and slightly shorter skull then lions while the latter are slightly taller at the shoulder on average (not only proportionally). Chest girth appears larger in Panthera tigris tigris but accounting for Ngorongoro Crater adult male lions estimated at 212 kg on average based on chest girth, reversing my formula (a thoroughly computed one) it would imply an average chest girth of nearly 1300 mm on live animals after expiration (as normally measured) and therefore pretty much as the highest Indian tiger averages computed from hunting records (all animals obviously dead and therefore at least some possibly affected by post-mortem inflation). Forequarters (particularly the distal elements) and hindquarters of big male tigers generally appears stockier then those of most big male lions. Chest of female lions generally appears proportionally wider then chest of female tigers in pictures and circumference of the largest and bigger lion population seems to cautiously confirm this feeling. I believe modern Indian tigers are slightly bigger on average then modern African lions because of a combination of different elements including prey size, density and typology, habitat characteristics, sociality, and interspecies and intraspecies competitions. The difference in average body mass is marginal and in my opinion around the rounded figure of 10 % (it can also be 5 %, 12 % or 15 % I do not much care as it depends from which data one includes) or so comparing either the populations as a whole or the largest / heaviest ones for each (for instance northern India and Nepal tigers with Ngorongoro Crater lions). It is just because the difference is so marginal, debatable and manipulable that size of lions and tigers has been vigorously discussed and will still heatedly be discussed for ages with little or no chances to find a common and peaceful agreement. Also because for any reliable actual weight of a very big tiger thrown in the scene, one can always find a similarly reliable weight of a lion individual comparable to the former. The story will likely never ends. WaveRiders
It is hard to calculate the exact bone density between these two cats.
And the most intuitive way for the comparison is to compare the canine density between the two cats. As the tiger canine is generally heavier and more robust, so it gives a general impression that the tiger has higher bone density. However, I am just not sure if the canine density can represent the overall bone density.  (02-02-2015, 07:18 PM)'WaveRiders' Wrote: While I too noticed that Panthera leo usually has slightly longer and wider bones than Panthera tigris, I do not agree on the statement that bone density is higher in the latter then in the former. It is also not clear what it is meant by bone density. Generally density of bones are compared from the ratio of their wet mass to their wet volume measured while fully submerged in water for at least 15 minutes. Bone density can also be ascertained by their mechanical properties and by the bone mineral composition. In a study I did long time ago on skeletal properties of carnivore limb long bones, I concluded that Panthera leo appears to have slightly higher either cortical area and principal moments of inertia then Panthera tigris. This is compatible with the higher bone stresses occurring in fast locomotion of a more cursorial species. Therefore lion bones appear to likely be more then just slightly more robust as the higher external robustness in all compartments (proximal and distal epiphysis and diaphysis) is also corroborated internally. Are you only using Captive Lions in this assumption? Did you use captive tigers as well? Just curious what animals you used when researching? In regards to bone densisty testing I was under the assumption that "The most widely recognized BMD test is called a dual-energy x-ray absorptiometry, or DXA test. It is painless—a bit like having an x-ray." In regards to this statement "I believe modern Indian tigers are slightly bigger on average then modern African lions because of a combination of different elements including prey size, density and typology, habitat characteristics, sociality, and interspecies and intraspecies competitions. " I don't agree with it. If you were to simplify why tigers are larger than lions it would be because they are longer and usually have larger forelimbs. This is a genetic trait, while both have similar shoulder height and chest girth their limb robustness is what I find to be the largest difference between them. If you were going to say that their forelimbs are larger because of their solitary lifestyle I guess it would tie into what you have written. But plenty of lions hunting by themselves or with little help from pride members, they have a far higher selection of food to choose from and hunt durations are very similar between either animal. Both are ambush predators not built for long chases. If I were to guess why lions have thicker bones it might have to do with terrain, since they run on flat hard surfaces. But if you were to try and compare, you would need to use Corbett tigers which have more of a rocky surface compared to a Assam Tiger which lives in a marsh land. Etc. I know tigers have specifically small colar bones to make room for their robust fore limb muscles so we would need to see if any of these morphological differences took place in other tigers from different areas. The data is almost non existant in wild tigers so its impossible to compare. Since captive tiges are mixtures of many different sub species its not going to give you a true idea. You will get some tigers who are massive and others who are smaller. Like what we already see now in captivity. "Chest of female lions generally appears proportionally wider then chest of female tigers in pictures and circumference of the largest and bigger lion population seems to cautiously confirm this feeling." I have also seen nothing to confirm this statement ^^ "Also because for any reliable actual weight of a very big tiger thrown in the scene, one can always find a similarly reliable weight of a lion individual comparable to the former. The story will likely never ends." ". The difference in average body mass is marginal and in my opinion around the rounded figure of 10 % (it can also be 5 %, 12 % or 15 %" Agreed, from the weights I have seen, its usually a 15kg-40kg difference (tiger being heavier) when comparing averages or maximums. Which is right around the 10%-15% range 
~~Agreed, from the weights I have seen, its usually a 15kg-40kg difference (tiger being heavier) when comparing averages or maximums. Which is right around the 10%-15% range
I disagree. Crater lions, at an estimated average for full grown males of 212kgs, are extremely close in size to the largest tiger subspecies, estimated at 221 kgs. (adjusted, small sample ). Not much of a difference; at all. Peter summed it up quite accurately. Tigers reach extremes more often. There simply isn't enough recorded data on craters and Okavangos, along with Kazirangas to accurately guage the size difference between the largest subspecies of each. I believe its much closer than you claim. The largest tigers eak it out over the largest lions. 
How much longer is the bengal tiger compared to the african lion? If it came down to length then wouldn't the Siberian have the potential to be the biggest feline since they are the longest wild cats.
The Crater 212 kg sample was of 6 specimens, 1 less than the Nepal sample published and 3 less after the two other 272+ kg males. If the other 200 kg sample is added, we have 206 kg average from 12 specimens. Also, a question, this was their equation: mass = 1.84 * girth - 189.11, meaning the average girth they had for the sample was 218 cm. There's an error somewhere if someone can help me find it, either on my part or the print. A slope of 2.84 would make more sense, as the 212 kg weight accounts to a 140 cm girth.
On length, Peter covered it well, Bengals are slightly longer, I believe. Amurs are the longest, but they are proportonately light in modern times at least, so the length does not reflect in their mass. 
In fact, that equation for Crater lions is wrong. Apollyon discussed that with Dr Packer and they proved that the calculations were incorrect. So, the figure of 212 kg is inaccurate.
Hope this helps.  (02-04-2015, 10:18 AM)'GuateGojira' Wrote: In fact, that equation for Crater lions is wrong. Apollyon discussed that with Dr Packer and they proved that the calculations were incorrect. So, the figure of 212 kg is inaccurate. Is there any reliable estimate of weight of adjusted crater lions? Tiger mentioned 206 kg average - is that for adjusted lions? BTW as far as I know the average weight of african lions is around 180 kg, while average weight of bengal tigers is around 210 kg. Am I right? (02-04-2015, 08:42 AM)'tigerluver' Wrote: The Crater 212 kg sample was of 6 specimens, 1 less than the Nepal sample published and 3 less after the two other 272+ kg males. If the other 200 kg sample is added, we have 206 kg average from 12 specimens. Also, a question, this was their equation: mass = 1.84 * girth - 189.11, meaning the average girth they had for the sample was 218 cm. There's an error somewhere if someone can help me find it, either on my part or the print. A slope of 2.84 would make more sense, as the 212 kg weight accounts to a 140 cm girth. On top of everything else, the Tigers weights are estimated (adjusted) since the scales were bottomed out. The figure of 221kg is a very conservative guess. TBH I think its to conservative but thats just my opinion. (02-04-2015, 01:55 PM)'Amnon242' Wrote:That is pretty accurate. I think its definitely on the conservative side for both species, but that is a good "average" for both of them.(02-04-2015, 10:18 AM)'GuateGojira' Wrote: In fact, that equation for Crater lions is wrong. Apollyon discussed that with Dr Packer and they proved that the calculations were incorrect. So, the figure of 212 kg is inaccurate.
The number I posted was from the same document with the faulty equation, so the 200/206/212 kg estimates must be disregarded and we've no data on that population.
(02-04-2015, 11:11 PM)'tigerluver' Wrote: The number I posted was from the same document with the faulty equation, so the 200/206/212 kg estimates must be disregarded and we've no data on that population.http://www.cbs.umn.edu/sites/default/fil...ongoro.pdf ^^ That is packers studies of Crater Lions. -The crater is only 25km west of the Eastern portion of the Serengetti -Crater lions are severely inbred, they have had 7 breeding males enter the crater from elsewhere in the past 27 years -There was a plague that wiped out many crater lions and then the next 3 sets of breeding males where probably immigrants from after the plague then after the 70s all breeding males have been born in the crater. -Crater male coalitions have totaled 15 males and presumably no matter the coalition size, usually only 2 or 3 males will actually breed. That size of the coalitions has been one of the causes of the inbreeding since the nomadic males that have ventured in have not been able to dethrone the large coalitions. No weights or description of excessive Lion size are given. The fact that there have been lions from other parts that have entered and bred, shows that there would most likely be no difference in size between them and other Serengeti lions. Its worth a read, if you guys get a chance. 1) The bone density testing that you are referring is a bone mineral density test (BMD). The mineral composition of a bone obviously affects its strength, but it is the way the bone material is distributed macroscopically that makes the difference in the mechanical properties unless the animal suffers of osteoporosis or other bone sickness. The size, shape and proportion of the bone section to its length dominate the overall mechanical properties of a bone. One parameter easy to evaluate is how a bone is heavy relative to its volume (macroscopic density) and this is done in the way I highlighted, meaning measuring its wet mass and wet volume. 2) I specifically referred to captive lions only in the study concerning the ratio of the skeletal mass to body mass and in the ratio of muscle mass to lean/total body mass The animals were a captive adult female lion in excellent condition and a rachitic subadult male lion. Most of the qualitative and quantitative data/info I released refer to wild lions and wild tigers otherwise, consistently for both species, to wild/captive lions and wild/captive tigers. The majority of the qualitative info I highlighted has been investigated to a different extent, even quite deeply, by many published studies other then my study and they all substantially suggest very similar and rather consistent conclusions which is also mine. The data on the ratio of the vertebral column section and scapula length to the presacral vertebral column length and the ratio of the greatest length of processus articularis to the scapula length are unpublished data from my study. In this case I also used captive lions and captive tigers to increase the sample size of both species. I am not comparing cranial and dental characters where it is well known for over a century the significant effect of captivity and that therefore only wild specimens must be used. There are going to be effects of captivity on postcranial skeletal formation and characters too, but I used the same proportion of wild and captive individuals for both species. Using wild specimens only for both species the conclusions do not appear to change as the trends seem to be confirmed, but it is clear that it would be better to investigate the matter using more individuals for both species. The problem is that there are few data available of definite wild individuals and few complete skeleton of wild individuals available for measurements from Museums and other Institutions unless travelling all around the world to find and measure as many as possible. The process to study and measure a complete skeleton is long, complex delicate as you can imagine. In any case bear in mind that it is always a close call between tigers and lions cranial and postcranial parameter comparisons. As a further note I highlight that the tiger may have an overall edge in the distal forelimb elements radius and ulna. It is a very close call with some parameters suggesting more robustness in the tiger others in the lion. The relative length of the oleocranon process to the ulna length may actually be longer in Panthera tigris then in Panthera leo. Overall I would suggest the tiger has a slight edge in robustness of the radius/ulna compartment as well as in the solidity of the front paw (proportionally longer in the lion). As I wrote before instead basically all robustness parameters of humerus, femur and tibia from external dimensions and cortical area appear higher in the lion then in the tiger. In terms of heart mass to total body mass and lung mass to total body mass ratios data from published studies appear to suggest the lion has an edge over the tiger. These trends and the higher overall relative robustness of the limb long bones of the lion compared to those of the tigers (with likely exception of the radius and ulna) appear to me consistent, as I wrote before, with the higher endurance demands and the higher bone stresses occurring in fast locomotion of a more cursorial species like the lion is compared to the tiger. 3) If you meant that what at the end makes an average Indian/Nepal tiger somewhat heavier then an average African lion is primarily a slightly longer body length (exacerbated by the slightly longer skull in the lion) is a fair conclusion. This is however the final effect. I instead highlighted what could have caused the evolution to follow this direction. Bear also in mind that Indian/Nepal tigers appear more sexually dimorphic then African lions and that sexual dimorphism in tigers is highest in the two largest forms (Indian sub-continent on one side and Manchuria, Amur-Ussuri region on the other side). I believe the convergence at a particular average body size for both species is also partly due to the evolutionary pressure coming from their polygynous mating system which is the same among the Felids but emphasized from being applied to the two largest species as well as the two apex predators of their respective ecosystem (the brown bear is not a pure predator). However the social system of lions and tigers is different and there are an evident sexual character difference of the male lion compared to the female lion (the mane perhaps limiting or not requesting a too high sexual dimorphism for a social carnivore living in open woodlands and savannah). As highlighted in my previous post there are also different evolutionary pressure from the preferred habitat characteristics, the large prey size that tigers are able to consistently hunt alone, prey density and typology, and from the extent of interspecies and intraspecies competition in relationships to the social system. Most of the African open woodlands and savannah is a significant tougher habitat then the Indian jungle. Lions are social carnivores (to a different extent among population depending from density and other general parameters) because that is the way they can increase individual success and because they can better compete against clans of spotted hyenas and packs of wild dogs in areas where the density of these animals is high. African lions could have evolved becoming much bigger, as it occurred, likely for different reasons too, in Eurasia and North America during the Middle and Upper Pleistocene, but increasing body size has a cost and the African/Asian lion could not afford it. 4) Without recurring to my data, just check the average and maximum chest girth of Indian/Nepal tiger females from historical and recent data and compare those figures to average and maximum provided by Smuts et al. (1980) for Rhodesia and Kalahari female lions 4 years old and older and the maximum for Kruger NP female lions 4 years old and older. It appears that those female lions has a clear edge over Indian female tigers exceeding possible sample bias. WaveRiders |
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