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Pleistocene Big Cats
Freak Felids - A Discussion of History's Largest Felines
Freak Felids - A Discussion of History's Largest Felines
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Freak Felids - A Discussion of History's Largest Felines
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Panthera fossilis with a such monstrous skull still weighed less than 400kg?
Even the largest captive Amurs (non-obese specimens) weigh more than that. Maybe the cursoriality actually played a bigger role for the prehistoric pantherine cats than we previously thought? 
Looking at this map:
 *This image is copyright of its original author GrizzlyClaws, at least in my opinion you are correct that cursoriality was huge in the Pleistocene .Essentially, the lion clads whole Eurasian prehistoric range lacked forest. Open steppe-tundra calls for the abiity to run a lot and efficiently. The best way to achieve this is through long (greater stride), light (the lighter the less energy cost, yet wide bones (spread running impact stress across a large surface area to minimize damage). The lion clad have all three of these traits, suggesting a species supremely adapted for its environment. Middle to late Pleistocene tigers are a different story, as you see on the map, those areas are "temperate" and "tropical", in other words, forested to a significant extent. Limb length becomes limited due to the trees above, and at the same time running is not as necessary. With limb length limited and running not a focus, the species can only increase in mass by bone density and width. Leopards and jaguars also show these "symptoms" of forest life. On the MT3 reported by WaveRiders of 192 mm of P. fossilis, in accord with the ratios published by Day and Jane (2006), that specimen would be of 115 cm at the hip and 97 cm at the shoulder, assuming lion built, and a bit shorter assuming the other species' builts. Day and Jane (2006) use a pictoral method for their data, so there might be room for error as those numbers look too small to me. Furthermore, higher MT/Femur ratios is directly correlated to increased cursoriality, another piece suggesting how cursorial P. fossilis was. 
Giant Pleistocene felids and new fossils!!!
 *This image is copyright of its original author Can't say it better. [img]images/smilies/tongue.gif[/img]
I believe WaveRiders is discussing P. fossilis.
Also, WaveRiders, could you please direct me to the works on metacarpal/tarsal allometry of the fossil lions?
The adult female cave lion from the Siberian steppe. The cursoriality looks very similar to Panthera atrox such as the low density bone and hollow canine teeth.
Overall, we can assume that the Pleistocene lion fossils look very different from their tiger counterpart.  *This image is copyright of its original author
Here's the von Reichenau excerpt on, in my opinion, the largest specimen on record of P. fossilis.
 *This image is copyright of its original author 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.
Despite often reading P. spelaea was more proportionately robust than modern lions, I don't find any evidence to that assertion in the data. For one, most records are of fragmented bones. For example, Dawkins et al. (1866) has a few fragments of long bones, and a handful of full bones. The fragments are wider than the comparitive material of modern cats, but the relative robustness relative to length cannot be determined as most of the bone is missing. From the few complete bones the ratios are essentially identical to the modern lion. Nevertheless, most fossils inidicate an average size a bit larger than the modern P. leo, around 230 kg. There 470 mm skull mentioned by Marciszak (2014) is exceptionally large for the species. From that, P. spelaea probably did not exceed 330 kg, a bit larger than a freakishly large modern lion.
I've more indicators on the sheer robustness of P.t. soloensis after some more research. For one, a value I did not discuss that was published by vK himself was the AP diameter of the head. It was 59 mm. That is extremely massive. Let's put it into perspective. P. leo and its clad (P. atrox, P. speleaea, P. fossilis) is at least 10%-20% relatively more robust than P. tigris in the proximal end of the femur (Dawkins et al. 1866). An exceptionally robust P. atrox specimen had an AP diameter of head of 54.3 mm and length of 455 mm, an index of 0.119. The Ngandong tiger specimen had an index of 0.123. Considering how much more slender tiger bones are, the Ngandong tiger proximal AP diameter is absurdly thick. This published AP diameter of the head also supports my personal extropolated DAW and greatst proximal breadth, as a 59 mm diameter can only be of a bone with such dimensions (beyond the fact that vK actually differentaited between DAW and distal diameter in his book). But in terms of mass estimation, I don't have enough specimens to produce a good trendline, so no number will be produced by the AP diameter of the femoral head. Another measurement published by vK was the diameter of the distal notch of 23 mm. The DAW scales about 4.5-4.8 times the notch diameter, within the range of my DAW measurement of 107 mm. On a good note, I was able to find a third comparitive diameter of the Ngandong tiger femur, the lateromedial diameter of the midshaft. Christiansen and Harris (2005) list this diameter at the point of least circumference. The word "least" is a bit misleading. Egi (2001) clarifies the point of measurement, which is the 1/2 point of the length of the bone (AKA the midshaft) in femur and tibia and the 55% length point in the humerus as follows:  *This image is copyright of its original author Thus, I extropolated the third Ngandong femur measurement compatible with published databases, LM diameter of the shaft. The measure was 42 mm, much more robust than modern tigers and a bit shy of the most robust P. atrox femur. Thus, from the measurements of the femur length (480 mm, est. 409 kg), DAW (107 mm, est. 531 kg), and LM diameter of shaft (42 mm, 559 kg), the calculated mass of this specimen is 500 kg.
So the largest Ngandong tiger is 500kg, and don't you think it is a bit too much for a Panthera specimen?
BTW, the largest skull for P.spelaea is 451mm, and any skull that exceeds 460mm should be assigned to P.fossilis. http://17thstreet.net/2014/08/02/legenda...-part-one/
The mass estimates are very high, and essentially out of the modern world. The equations themselve are of extremely good fit for tigers. The numbers are mathematically produced and the only interpretation I applied was respect of significant digits, 3 digits as you can see. The Pleistocene subspecies were in a way, anatomically different from the modern panthera as we define today, so exact comparison is likely not accurate. 8% robusticity difference is very significant, cats were as robust as some modern bears, and the greatest bears of the time were rhino sized.
The 475 mm P. spelaea skull is dated from the transitional period according to Marciszak. The relationship between P. fossilis and P. spelaea is highly debated as I wrote on in article, but assuming P. spelaea did evolve from P. fossilis, the 475 mm would be "P. spelaea fossilis" of sorts. From the transitional period, its likely that there were still extremely large cave lion present even though the general gene frequency was being directionally selected for smaller size. Though, if Sabol (2011a) hypothesis is correct, then P. spelaea was a competing smaller species alongside P. fossilis. From the data, it's a matter of personal opinion. Do you think that a smaller species of cat on the mountains would efficiently keep the larger species on the lowlands? Were the prey on the mountains not large enough, or was it a lifestyle difference which caused the exclusion? The gradual evolution of P. fossilis to P. spelaea seems like an easier explanation to wrap the mind around. If the two forms were contemporary, competing, different species, the fossil record would have to be entirely reanalyzed. Wha would be their common ancestor? In my opinion, P. fossilis population that migrated to the mountains become separated and developed a distinct gene pool, and may have subspeciated rather than speciated. I assert subspeciation as there would likely still be occasional gene flow between the lowland and mountain populations every so often, preventing true speciation (reproductive isolation). Eventually, something caused the entire lowland population to either die out or completely migrate to the mountains. Here, either the official transition of P. fossilis to P. spelaea began or this was the moment the mountain populations returned to the lowland to dominate the entirey of northern Eurasia.
I think Marciszak has pointed out that the 451mm skull belongs to the transitional period, while the 475mm one belonged to the late evolutionary phase of P.fossilis.
BTW, what would be the body mass of a male Amur tiger that measures 4 feet tall at shoulder and 8 feet long with the head+body length?
Here's the Marciszak table with species classifications:
 *This image is copyright of its original author An 8 foot body length Amur tiger would likely be no less than 350 kg with modern wild Amur proportions. In modern Bengal proportons that would be in the low-mid 400s. A 4 foot by 8 foot is freakishly large for any modern species. That's about the dimension of the largest Ngandong tiger, but the robusticity would be different.
Check these two pages folks:
http://17thstreet.net/2014/08/02/legenda...-part-one/ http://17thstreet.net/2014/08/16/legenda...-part-two/ This article (divide in two parts) explain very well why the cave "lions" were NOT lions and that they don't hunted in group, as the cave paint suggested. Take a good read, it deserves the time. [img]images/smilies/smile.gif[/img]
As for the 475mm skull, it belongs to the Cromerian lion or the Cave lion?
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