Freak Felids - A Discussion of History's Largest Felines

[tigerluver]

Here's the von Reichenau excerpt on, in my opinion, the largest specimen on record of P. fossilis. 

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Beyond the giant length, the specimen looks to be relatively more roboust than at least the lion compared in the chart, here are the differences, in order of the format of the table:

*This image is copyright of its original author

 
Overall, the P. fossilis specimen is 8.37% more robust than the comparitive P. leo specimen. Unfortunately, I have no direct regression equation to give a mass for each dimension in the excerpt. Thus, I figured I'd allometrically scale the percent difference and apply it as a correction to the length derived mass estimate. Bone epiphysis diameters do not scale isometrically, but rather toward the 2.0-2.5 range. We'll go with the high end, so the specimen would be 22% heavier than a modern lion of the same ulnar length. Isometric comparison of the ulnar length with modern lions produced an estimate of 347 kg for the ulna (the other estimate I have given was with the entire Panthera genus via regression and not simple isometry, which significantly overestimated lions, but that's for a different discussion). Apply the correction factor, and the new estimate is 423 kg. In the end, I'd prefer a regression models to estimate each dimension, but the data is not available in literature and my local sources don't have many modern bones with the mass of the specimen actually recorded, plus measuring bones burns through time. One modern specimen for comparison also is not the best basis for the last word, but it's the best available for comparison.

It seems the prehistoric giant species were not only larger in height and length, but were more robust. P. atrox  was around 8% more robust bone-wise than the modern lion as well. The Ngandong tiger was 15% more robust than the mainland tiger subspecies, and about 8% more robust than the Javan form. 

With that, I've a correction to make. In a previous post, I stated a P. atrox specimen had a DAW of 120 mm. That was incorrect and was actually a width of the proximal epiphysis. The true DAW of this oddly robust specimen was actually 105.4 mm. Thus, P. atrox caps off at 370 kg from the fossil record.  Reply