Following with the estimation of weight of the
giant Cromerian lion (Panthera spelaea
fossilis), using my database and the same Excel sheet that I used for the
Ngandong tiger (see the Ngandong tiger topic for details), I calculated the body
mass for the skull specimen and the femur one.
Here are the results, average of all the
* Skull (CBL) - 433 mm: 510.3 kg
* Femur (GL) - 470 mm: 367.1 kg
Interesting, the skull-weight is way too high, just
like a bear. With such a large skull, I will estimate a figure of maybe up to 400 kg
and at simple sight, but 500 kg?
Surely NO, is like you say, it seems that skulls grow in a different way than
the body overall, so the body weight estimation of skulls could be over or
under estimated depending of the size of the specimen.
Now, with the femur, the estimation of C&H (2009)
was of 349.3 kg, using all Panthera
but only males. The estimation of Sorkin (2008) was of 385 kg (modern lion CBL
of 359.7, femur of 401.5 mm and a maximum weight of 240 kg). The final average
kg is very high, but with such massive animals it is be expected.
Well, this is the data that I have found; I think
that this will help you to establish the weight of this giant cat, just like we
have done with the Ngandong tiger.
I will put a new list of the skulls of the
Cromerian and the Eurasian Steppe lion, actualized with the new data from the
document of 2013.
Exactly why I have left usage of isometry out. Note, Dr. Christiansen also used regression in his latest document to calculate mass. I'm sure you saw how some species gave irrationally high estimates for the skull, such as the jaguar. The size limit for Pantherines seems to be in the low four hundred kilograms. This makes sense, as where one finds cats, one finds bears. Bears rules the 500+ kg size range, and thus rule the niche that comes with such size. Evolutionary, it would not be beneficial for cats to grow to the size of bears and compete for the same niche. S. populator
seems to make it to the mid four hundred kilogram range. I have some comparisons of S. populator
bones to bears to show their size.
The femur estimate you got is similar to the one I have found with regression. I assumed that P. spelaea had a build midway between tigers and lions and thus based the regression off a database of only tigers and lions. The database for the formula is based off of 6 specimens, the equation:
log(mass) = 3.6775*log(femur length) - 7.2568
The 470 mm femur would have a mass of 371 kg accordingly.
In all these estimates, if P. spelaea was truly lion it would be a bit lighter as lions have long bone dimensions with relatively less mass out of the Pantherines, around 350 kg.
Lastly, the Sorkin method is a bit unreliable because it mixes and matches masses and bone dimensions. For example, Christiansen and Harris (2005) have a lion weighing 203 kg with a femur length of 401 mm. According to Sorkin's method, he would use the 401 mm length with the greatest mass of lion on record, not 203 kg. Here, one can see the problem. Each extant specimen is like a trial. One can't mix and match data from two separate trials. This explains why Sorkin calculated overestimates for the specimens he assessed, as he used a 320 kg mass as the mass of the bone of the cat which did not weight nearly as much. Maybe for the sake of comparison between fossils this method is okay, but in terms is accuracy, not so much. For that reason, I would consider the Sorkin estimation of the femur invalid. A 401.5 mm femur clearly does not represent a 240 kg, so the basis of comparison is wrong. Furthermore, the Sorkin method is redundant with the isometry method. Averaging the Sorkin result based on only one specimen with the result of isometry applied across many specimen is giving the one base specimen used in the Sorkin method unreliable influence on the average mass. My recommendation is to stick to one method, not average different methods. Formulas are independent. New formulas are derived in hopes to gain accuracy, so I avoid mixing up the results of new and old methods, as doing so kills the purpose of finding more accurate methods of mass estimation.