Freak Felids - A Discussion of History's Largest Felines

[WaveRiders]

Hello to everybody,
 
after a few years since when I had to disappear again from AVA forum I recently enter the website to see what was going in it and realized it apparently mostly died. I therefore looked for where my old friends have been posting and find you in this board, read some quite interesting posts and decided to register.
 
First of all please allow me to congratulate to all of you for the excellent research and info you have keep going posting. Unfortunately my life does not allow me to be as consistent in posting as some of you are. I really wish I could.
 
Adrian Marciszak, Charles Schouwenburg and Robert Darga have definitely the great merit, among others, in their 2014 scientific publication (circulated in the internet since late 2013) on fossil lion size temporal evolution to have finally noticed and reported for the first time in 23 years after the original report the intact giant 3rd Metatarsal as long as 192 mm. This fossil remain is described together with many others as part of the initial findings of Dr Argant research in the Chateau Breccia published in a 1991 work. Marciszak and his co-authors described the size of this fossil as incredible.
 
I am very much grateful to them as it seemed before their publication I was the only one to have noticed the exceptional size of this specimen as well as that of another individual from the same site nearly as large as the former.
 
You may remember I wrote in early January 2012 in AVA about an absolute monster Panthera (leo) spelaea fossilis individual (I classify the species following a mix of the old school of thought from Kurten, Hemmer, Turner, Yamaguchi and others. as well as that from most recent taxonomy by Argant, Baryshnikov, Sotnikova and others) that got me sick and caused me headache thinking at his size. This has happened for many years particularly after I had the opportunity to discuss a few issues of the Chateau fossil remains with Dr Argant (several years before 2012) who basically confirmed me the measurements of that exceptional specimen.
 
The big boy was just the 192 mm MT3 individual! 192 mm of bone that nearly caused me a hearth attack when I was studying the first time the fossil carnivore material from Chateau.
 
On that circumstance Dr. Argant also confirmed me that another MT3 specimen missing the distal epiphysis I questioned him was estimated by him as likely long as ca. 190 mm if intact (I had estimated the total length at ca. 187 mm based on multi regression equations based on the other provided measurements). From my study on the Chateau Breccia large carnivores remains I concluded that the latter specimen was the remain of a 2nd huge individual different from the aforementioned one and just very slightly smaller and that therefore at least two monsters had found death in the cave. Throughout the years before 2012 I remember to have had discussions on those findings with likely at least two very much worldwide acknowledged fossil felid authorities, personal friends of mine, but with no follow ups.
 
Anyway, I still cannot believe that the size of this specimen(s) got unnoticed in the whole of the scientific community for 22 years but for me and the original author before 2013. I believe to date no other fossil felid specimen represented by any kind of complete or incomplete cranial or postcranial bone or teeth whose measurements have been either published or unpublished but known to me matches him in body size and mass although a few other fossilis and spelaea specimens are not too far off from it and the heaviest Smilodon populator individuals are also reasonable close to him in body mass (but not in overall size).
 
Has somebody an idea what does it mean a fossil lion with a 192 mm MT3? If not think that the MT3 of a modern average male lion falls in the range 135-140 mm and that of a large modern male lion in the range 140-145 mm. We are therefore talking of a major metapodial of a lion-like creature over 40% and over 33% larger then the one of an average size and of a large Recent male lion respectively! Although in the case of Middle Pleistocene lion it is much harder to get conclusions on allometric relationships to get external body proportions with the same amount of accuracy then for the Upper Pleistocene form, to be conservative we can apply isometry instead of the possible slight negative allometry of MT3 of the Upper Pleistocene form compared to the modern lion as suggested by several authors as well as by me. This negative allometry appears to be supported by the apparent elongation of second and fifth MT, as well as MC, with respect of 3rd and 4th MT  and MC respectively suggesting a less specialized cursorial morphometric adaptation of P. spelaea with respect of P. leo. My past studies additionally suggest skull size and body size raise from a likely slight negative allometry with respect of MT3 length in Panthera leo to a likely fractionally positive one in Panthera leo spelaea (isometry in all cases is strongly included in the 95% Confidence Interval). To let understand the matter better to all of you I summarize the concept saying that it appears a fossil lion with a 192 mm MT3 would likely be slightly larger then a modern lion individual with a 192 mm MT3 (assumed that were possible and it is not). Irrespective of using allometric or isometric regression equations, we are going to materialize a true monster felid which you may remember I estimated weighing most likely 385-405 kg with best estimate 390+ kg. I have not refined my quite complex models since mid 2012 due to other priorities despite some new findings and my ever expanding database, but I believe I would still fall into numbers close to those figures (ca. 395 kg). In accordance to what I briefly suggested in an old post in AVA forum I state again that according to my models the straight line head-and-body length of this individual would likely have approached 2550 mm and the standing shoulder height nearly 1400 mm. I also estimate the greatest skull length likely approaching 530 mm and the condylobasal length over 460 mm. That was a hell of a cat!
 
I therefore found the 192 mm MT3 individual somewhat incompatible for size with the 484,7 mm skull specimen revealed in Marciszak et al. (2014) paper following Argant unpublished data, and, to a slightly lesser extent, the incomplete 187-190 mm MT3 individual as well. At the time I talked with Dr. Argant many years ago he actually anticipated me that the diggings restarted in 1996 had recently terminated (2007) and that much more material was going to be studied. He told me many more remains either intact, incomplete or fragments have been found. Unfortunately I had no opportunity to talk again with Dr Argant and visit him and his new collection. Hopefully it will be possible for me to do it in the future.
 
Other then the two extremely large MT3 within the Chauteau sample published in details to date there are some very large calcanei and astragali, a few very large incomplete femora and another MT3 fragment with a very large distal epiphysis whose length I estimate ca. 178 mm (170-180 mm if you like). Additionally we have one large and one very large skull whose prosthion-inion length of 465 mm and 484,7 mm have recently been unveiled although the existence had been anticipated in 2007.
 
The fossil lion sample from Chateau described by Argant in 1991 and successively following the excavation started in 1968 is exceptional for the average size and size range of the specimens. The sample show an evident bimodal size distribution suggesting very much marked sexual dimorphism. When I studied the Chateau carnivore remains well over a decade ago I sexed 6 fossil lion specimens as females and 24 as males, a figure raised to 26 with the two skulls from the Northern Section whose total lengths and least breadth at the canine alveoli have been generously anticipated by Argant to Marciszak et al. for their 2013/2014 publication. In the attempt to provide a scientifically solid enough suggestion of how many distinct individuals these 32 specimens represent considering the available information of stratigraphy distribution, taphonomic study of the bone accumulation, body side and size compatibility. I cautiously suggest that they could be as low 4 males and 2 females to at least 6 males and 3 females. In recent years I have been anxiously awaiting for new detailed reports as nearly 10 years ago Argant anticipated 4 complete and 13 fragmented skulls, 8 complete and 15 fragmented hemimandibles, a few tenths of complete and fragmented limb long bones and over 100 complete and fragmented metapodials, etc. for a total of 929 remains (including an incomplete skeleton and several articulated bones belonging to the individual having the 484,7 mm skull as well to other individuals) were found in the Northern Section. He has not yet described them in details. The number of fossil lion individuals from Chateau can therefore well substantially rise and be counted in 2 figures.
 
From the study I did over a decade ago based on Argant (1991) material it appears that the two huge MT3 individuals and the recently unveiled 484,7 mm skull individual are, to my current knowledge, the three largest individuals from Chateau. I estimate the latter individual at around 355 kg, most likely in the 345-370 kg range. This skull specimen matches very well the size of the aforementioned MT3 fragment estimated by me likely 175-180 mm in total length and that of other remains, but I cannot say if belonging to the same individual or not due to a number of issues featuring the site including mudflows occurring over time and lack of enough information on the most recent excavations. Most other male specimens, including the individual with 465 mm skull, fall into the weight range 300-350 kg and approximately 23% of them most likely in the 280-300 kg range.
 
As I wrote in AVA over 3 years ago my most likely average body mass range for fully adult Panthera (leo) spelaea fossilis males is not less then 250 kg and up to the unbelievable figure of 315 kg. Best estimates of average weight fall around 305 kg (280-315 kg) for males and around 185 kg (180-195 kg) for females. My best averages for Chateau Breccia male and female fossil lion samples approach the figures of 325 kg and 200 kg respectively.
 
Again, as I wrote in AVA over 3 years ago, I firmly state again that till new evidence will suggest differently in the future, I have and I have always had NOT A SINGLE DOUBT for very many years that the gigantic Cromerian Panthera (leo) spelaea fossilis has been the largest felid and the largest fossil lion form ever existed challenging the monstrous Lujanian Smilodon populator as the heaviest felid, but more then likely not topping him in body mass.
 
I hope now there are no more doubts on what I firmly stated years ago on the average size of Panthera leo fossilis and its largest unearthed individual.
 
 
                          WaveRiders
 

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