(06-02-2022, 05:50 PM)jrocks Wrote:

(06-02-2022, 08:40 AM)LonePredator Wrote:

(06-02-2022, 08:12 AM)jrocks Wrote:

(06-02-2022, 07:54 AM)LonePredator Wrote:

(06-02-2022, 06:56 AM)jrocks Wrote:

(06-01-2022, 08:46 PM)GuateGojira Wrote:

(06-01-2022, 10:15 AM)LonePredator Wrote: If you use the Van Valkenburgh formula to estimate Lions then the weight will be a huge underestimation, if you estimate Tiger, it will still be a big underestimation and if you estimate Smilodon Populator then it will be a big overestimation.

Actually it will be a gross overestimation, and here is an example, using the biggest CBL from the Panthera cats, taken by scientists, here you can see the weights calculated (in red) and at the right the maximum weights actually recorded (in blue):

Formula use: log mass = 3.11 * log CBL - 5.38 - Van Valkeburgh (1990) - only felids.

Tiger - 342 mm. = 316.8 kg (Est.) ---- 260 kg (Real)
Lion - 355 mm. = 355.8 kg (Est.) ---- 250 kg (Real)
Jaguar - 280 mm. = 170.1 kg (Est.) ---- 148 kg (Real)
Leopard - 256 mm. = 128.7 kg (Est.) ---- 96 kg (Real)
Snow leopard - 174 mm. = 38.7 kg (Est.) ---- 52 kg (Real)

Now we can see why thise formula is not reliable, not with Panthera cats at least.

would using the van vaulkenburg formula on populator skulls create huge overestimations as well, also i think a way to get an exact weight for the biggest populators is to scale it up from the skull of bonaerensis 46, as the entire skeleton of bonaernesis 46 managed to get completely preserved, although its just my opinion and i dont really know to much so idk

That would still not be a good way to estimate because of the same reasons as I described previously.

And yes, a big overestimation is possible but how big or small can’t be said with absolute certainty. Let’s just say it was somewhere between 350-400kg rather than 436kg since apparently some felids with relatively even smaller skulls were used to make this equation.

i feel like it would be best if smilodon bonaerensis 46 was between 350-400 kg, the reason i think that is because the largest populator specimen christiansen and harris estimated was 360 kg, and smilodon bonaerensis 46 was even bigger than that 360 kg specimen christiansen and harris estimated in 2005. christiansen and harris also said that there were large specimens of populator that exceeded 400 kg, and they said that in their study in 2005. 2005 is before the 15.4 inch uruguay skull and the 16.07 inch skull were taken into account, both skulls of which are now considered the 2 largest specimens of populator and both of those skull specimens are much larger than bonaerensis 46

I don’t know the exact measurements of the specimens you are mentioning. Do you have all the bone measurements of all these specimens? And also the measurements of the 360kg specimen estimated by Christiansen and Harris?

Maybe if we have the measurements then we might be able to make a better comparison and get a rough idea of their weights.

But once again, we can’t say from minor skull variations that the whole specimen was bigger. The difference in skull size is not that much after all.

https://peerj.com/preprints/2327.pdf

this is a sherani study from 2016, it says on the 15th page that christiansen and harris estimated that the largest of the same specimen did not exceed 360 kg, and because of that i think the specimen that sherani puts as 450 kg is the one that christiansen and harris put as 360 kg, although i dont know for sure if that same largest specimen was the one chrisitansen estimated at 360 kg as i cant get access that full christiansen paper. what i do know for sure is the specimen christiansen and harris estimated to be at 360 kg is smaller than smilodon bonaeresis 46, and tigerluver said that himself, you should ask tigerluver or guate to make sure the 374.5 mm humerus is the specimen christiansen estimated at 360 kg, below here is a link for i think the entire skeletal measurements of bonaerensis 46

https://wildfact.com/forum/topic-smilodon-bona%C3%ABrensis-46-the-forgotten-skeleton-that-defined-a-species

(06-02-2022, 06:07 PM)LonePredator Wrote:

(06-02-2022, 05:50 PM)jrocks Wrote:

(06-02-2022, 08:40 AM)LonePredator Wrote:

(06-02-2022, 08:12 AM)jrocks Wrote:

(06-02-2022, 07:54 AM)LonePredator Wrote:

(06-02-2022, 06:56 AM)jrocks Wrote:

(06-01-2022, 08:46 PM)GuateGojira Wrote:

(06-01-2022, 10:15 AM)LonePredator Wrote: If you use the Van Valkenburgh formula to estimate Lions then the weight will be a huge underestimation, if you estimate Tiger, it will still be a big underestimation and if you estimate Smilodon Populator then it will be a big overestimation.

Actually it will be a gross overestimation, and here is an example, using the biggest CBL from the Panthera cats, taken by scientists, here you can see the weights calculated (in red) and at the right the maximum weights actually recorded (in blue):

Formula use: log mass = 3.11 * log CBL - 5.38 - Van Valkeburgh (1990) - only felids.

Tiger - 342 mm. = 316.8 kg (Est.) ---- 260 kg (Real)
Lion - 355 mm. = 355.8 kg (Est.) ---- 250 kg (Real)
Jaguar - 280 mm. = 170.1 kg (Est.) ---- 148 kg (Real)
Leopard - 256 mm. = 128.7 kg (Est.) ---- 96 kg (Real)
Snow leopard - 174 mm. = 38.7 kg (Est.) ---- 52 kg (Real)

Now we can see why thise formula is not reliable, not with Panthera cats at least.

would using the van vaulkenburg formula on populator skulls create huge overestimations as well, also i think a way to get an exact weight for the biggest populators is to scale it up from the skull of bonaerensis 46, as the entire skeleton of bonaernesis 46 managed to get completely preserved, although its just my opinion and i dont really know to much so idk

That would still not be a good way to estimate because of the same reasons as I described previously.

And yes, a big overestimation is possible but how big or small can’t be said with absolute certainty. Let’s just say it was somewhere between 350-400kg rather than 436kg since apparently some felids with relatively even smaller skulls were used to make this equation.

i feel like it would be best if smilodon bonaerensis 46 was between 350-400 kg, the reason i think that is because the largest populator specimen christiansen and harris estimated was 360 kg, and smilodon bonaerensis 46 was even bigger than that 360 kg specimen christiansen and harris estimated in 2005. christiansen and harris also said that there were large specimens of populator that exceeded 400 kg, and they said that in their study in 2005. 2005 is before the 15.4 inch uruguay skull and the 16.07 inch skull were taken into account, both skulls of which are now considered the 2 largest specimens of populator and both of those skull specimens are much larger than bonaerensis 46

I don’t know the exact measurements of the specimens you are mentioning. Do you have all the bone measurements of all these specimens? And also the measurements of the 360kg specimen estimated by Christiansen and Harris?

Maybe if we have the measurements then we might be able to make a better comparison and get a rough idea of their weights.

But once again, we can’t say from minor skull variations that the whole specimen was bigger. The difference in skull size is not that much after all.

https://peerj.com/preprints/2327.pdf

this is a sherani study from 2016, it says on the 15th page that christiansen and harris estimated that the largest of the same specimen did not exceed 360 kg, and because of that i think the specimen that sherani puts as 450 kg is the one that christiansen and harris put as 360 kg, although i dont know for sure if that same largest specimen was the one chrisitansen estimated at 360 kg as i cant get access that full christiansen paper. what i do know for sure is the specimen christiansen and harris estimated to be at 360 kg is smaller than smilodon bonaeresis 46, and tigerluver said that himself, you should ask tigerluver or guate to make sure the 374.5 mm humerus is the specimen christiansen estimated at 360 kg, below here is a link for i think the entire skeletal measurements of bonaerensis 46

https://wildfact.com/forum/topic-smilodon-bona%C3%ABrensis-46-the-forgotten-skeleton-that-defined-a-species

I haven’t read that Sherani study very thoroughly but I don’t consider it reliable and it also says non peer reviewed. In that same study where he states the maximum weight of the Populator at 450, he also says that the Ngandong Tiger’s maximum weight as 480kg (in that same study) and I have not heard of any bone measurements of Ngandong Tigers which would give them that weight either through isometric scaling or any regression equation.

He also didn’t simply scale it with isometry but he has done something more with it which he apparently devised himself though I have yet to read all that part in detail but a straight isometric scaling or regression equation using other literature figures may be accurate than this.

It’s not possible for me to calculate without taking another one as reference, if you can give me the measurements of the 360kg Christiansen specimen then only would I be able to estimate the Bonaerensis specimen by using the Christiansen specimen as reference.

And although I haven’t thoroughly observed and estimated all the giant populator specimens myself, I have seen the maximum weight of Populator being stated at just above 400kg so I think 430kg may be the highest for Smilodon Populator.

And the 436kg estimate from Valkenburgh was definitely an overestimation now that I have seen the results of that method.

(06-02-2022, 08:40 AM)LonePredator Wrote: I don’t know the exact measurements of the specimens you are mentioning. Do you have all the bone measurements of all these specimens? And also the measurements of the 360kg specimen estimated by Christiansen and Harris?

Maybe if we have the measurements then we might be able to make a better comparison and get a rough idea of their weights.

(06-03-2022, 05:38 AM)GuateGojira Wrote:

(06-02-2022, 08:40 AM)LonePredator Wrote: I don’t know the exact measurements of the specimens you are mentioning. Do you have all the bone measurements of all these specimens? And also the measurements of the 360kg specimen estimated by Christiansen and Harris?

Maybe if we have the measurements then we might be able to make a better comparison and get a rough idea of their weights.

I have the document of 2005, so I can provide the measurements of those bones. And in fact, "Smilodon bonaerensis 46" is bigger than all the specimens used by Christiansen & Harris. 

I will try to put them tomorrow, if not until Tuesday.

(06-08-2022, 04:18 AM)jrocks Wrote: does anyone know if the smilodon specimens that christiansen and harris claim in the 2005 study exceed 400 kg are included in the study, or is that specimen they put at 360 kg the largest one in that study

(06-08-2022, 06:10 AM)GuateGojira Wrote:

(06-08-2022, 04:18 AM)jrocks Wrote: does anyone know if the smilodon specimens that christiansen and harris claim in the 2005 study exceed 400 kg are included in the study, or is that specimen they put at 360 kg the largest one in that study

No, the heaviest one in the study is of 358.4 kg, and latter they suggested that bigger specimens exist, apart from the ones studied, and they estimate that larger specimens could weight over 400 kg.

By the way, sorry that I could not share the data today, I will try tomorrow, I am busy now.

(06-20-2022, 09:18 PM)LonePredator Wrote: @GuateGojira @tigerluver Do you think it’s possible that Smilodon Populator may have had much more extra bodyfat compared to other cats which may have given them such robust bones??

As one of the significant reasons for Bear bones being so robust is because those bones have to carry a lot of bodyfat which has resulted in thicker bones to be able to carry that fat. Is it possible that it was something similar in case of Smilodon Populator??

(06-20-2022, 09:50 PM)GuateGojira Wrote:

(06-20-2022, 09:18 PM)LonePredator Wrote: @GuateGojira @tigerluver Do you think it’s possible that Smilodon Populator may have had much more extra bodyfat compared to other cats which may have given them such robust bones??

As one of the significant reasons for Bear bones being so robust is because those bones have to carry a lot of bodyfat which has resulted in thicker bones to be able to carry that fat. Is it possible that it was something similar in case of Smilodon Populator??

Cats do not storage fat in the wild at the same level as bears do, not even close. And even the amount that they save, like in the Amur tigers, are just for heating purposes, not for reserves, as cats do not hibernate.

I think that the bones robusticity on Smilodon is direcly related with muscles, although like any other animal, they were able to had some fat amount, but just the necesary like any regular cat in the wild.

(06-20-2022, 10:03 PM)LonePredator Wrote: Yes, the hibernation, yes. Why couldn’t I think of that. This makes me wonder, what would ther forelimbs have looked like. Modern Tigers have very bulky and muscular forelimbs and Populators should only look even bulkier.

Do you think this is a good representation of their forelimbs or do you think this is too much or too less??

*This image is copyright of its original author

*This image is copyright of its original author

And wasn’t the Ngandong Tiger limb bones also bulkier than modern Tigers?? So the Ngandong Tiger and the Pleistocene Tiger of Borneo would also have slightly bulkier limbs, right??

(06-20-2022, 10:22 PM)GuateGojira Wrote:

(06-20-2022, 10:03 PM)LonePredator Wrote: Yes, the hibernation, yes. Why couldn’t I think of that. This makes me wonder, what would ther forelimbs have looked like. Modern Tigers have very bulky and muscular forelimbs and Populators should only look even bulkier.

Do you think this is a good representation of their forelimbs or do you think this is too much or too less??

*This image is copyright of its original author

*This image is copyright of its original author

And wasn’t the Ngandong Tiger limb bones also bulkier than modern Tigers?? So the Ngandong Tiger and the Pleistocene Tiger of Borneo would also have slightly bulkier limbs, right??

Make it a little more bulkier, Smilodon was a very robust.

I remember that @tigerluver mentioned that the bones of the Ngandong tiger were a little more robust than those of modern tigers, but I don't remember how much, but probably they looked like the musculature of a large Bengal tiger. About the Borneo tiger, we have no idea as we only had a partial mendible, so we can only guess.

(06-20-2022, 10:37 PM)LonePredator Wrote: Okay, I did that, probably looks better now.

*This image is copyright of its original author

*This image is copyright of its original author


And about the Borneo Tiger, it makes sense that it may have been more robust since it had to carry more weight and to maintain the same agility and explosiveness as modern Tigers at such weight, it would need to be bulkier and muscular.

• The main reason for Brown Bears having very robust bones is the extra mass from body fat while Smilodons had muscle and since muscle is denser than fat, it would have lower volume per unit mass while fat would have higher volume and thus appear ‘thicker’.
• Muscle is motile while fat is immotile, the motile property of muscle would allow it to resist and ease up some of the stress on the limb bones while fat would exert a lot more stress on the mass on the limb bones (which would require thicker bones)