Freak Felids - A Discussion of History's Largest Felines

[WaveRiders]

 
1)         Christiansen database
 
“The outlier was removed after email contact with a staff at the museum regarding the specimen's health at death, when it was weighed. The 220 kg tiger is actually 230 kg, confirmed by future works of Christiansen and another author (Campione, 2012) who posted a huge database on animal femurs and humerus.”
 
 
You have to ask yourself why Christiansen used what you believe is an outlier. It seems that you have a animal stereotype, tigers, that all must be bulky otherwise there is something wrong with them. It also seems that you assume Christiansen has no way to judge the range of individual variability in tigers. Statistics cannot introduce bias to aim generating realistic and sensible results. It also seems sometimes you used that individual in your database (body mass vs condylobasal length of skull) other times you did not (body mass vs femur length) seemingly by judging how well the data fits the regression.
 
I stick with Christiansen consideration to consistently include tiger CN5697 in my database.
 
Concerning the tiger CN5698 220 kg / 230 kg issue
 
Christiansen & Harris (2005) uses 230 kg
Christiansen & Adolffsen (2007) uses 220 kg
Christiansen & Harris (2007) uses 220 kg
Mazak, Christiansen, & Kitchener (2011) uses 230 kg
 
Campione (2012) felid data have been taken by Christiansen & Harris (2005) database. I bet he did not bother to check any inconsistencies as he should have done for several more among the 255 animals and 1020 data he included as he took part of his data from existing literature.
 
It therefore seems to me that 220 kg or 230 kg is given on a random basis. There are a few other inconsistencies of Christiansen database

 
 
2)  Shoulder height
 
“Day and Jane's equation was based on the animal in the flesh, so all that you have brought up had been accounted for.”
 
It seems you have not followed me. The definition of the forelimb in Day & Janes (2007) does not include the scapula. Let’s do the math and the add the scapula you forgot to include..
 
From Day & Janes (2007)
 
Lion Forelimb %
 
Humerus -  37.4%
Radius 34.9%
Metacarpal   15.0%
Phalanges  12.8%
 
Lion Forelimb %
 
Femur   36.4%
tibia   37.3%
Metatarsal   16.7%
Phalanges   9.7%
 
Lion Hindlimb / Forelimb %   =  1.19% (1.1884%)
 
 
For a 192 mm MT3 fossil lion and assuming fossil lion had the same limb proportions of modern lions you calculated in post # 89 a hip height of 115 cm (192/0.167) and a shoulder height of 97 cm (1150/1.1884=968 mm) with a comment that those numbers looked too small for you.
 
I raised the point that you forgot to include the scapula as a contribution to estimate the shoulder height and the vertical distance between the acetabulum and the top foremost point of ilium to estimate the hip height.
 
I can tell you that a scapula of a such a huge fossil lion was likely to measure between ca. 390 mm and ca. 420 mm with 407 mm a likely best estimate.
 
Therefore 968+407 = 1375 mm
 
In reality it should be considered the anatomical position of the forelimb and scapula, the fact that longest phalanges should not be considered in length but in thickness, the pad thickness and the skin thickness. At the end a reasonable calculation gives a range 1350-1400 mm making therefore the 1377 mm figure pretty much a good estimate as a standing shoulder height.
 
I have to say that the above calculation following Day & Janes (2007) producing what in my opinion is a sensible shoulder height estimate accounting for the scapula is more the fruit of circumstance then anything else because the limb ratios % given by Day & Janes (2007) are approximated as based on stickers. For instance if you have to calculate the crural index in each felid species the results would be completely wrong as the tibias % appear consistently much longer then the respective femur % but in the ocelot suggesting the position of the knee sticker (or perhaps of the hip sticker) does not reflect the actual osteological ratio between femur and tibia. Should this have happened for the metatarsal sticker the above calculation could have produce a hindlimb, a forelimb length and a standing shoulder height rather different then 1150 mm, 968 mm and 1350-1400 mm respectively.
 
My model does not use Day & Janes (2007) data. I believe it is as much rigorous and accurate as reasonably possible. Yet I obtain a result nearly identical of 1375 mm, but honestly I did not even care to compare them.
 
 
3)   Metatarsal
 
“What basis did you use your body length estimation, as based on published data, 2500 mm is a bit of an overestimate. Here I could slide in a "bias" accusation as you did again a few times, but I'd rather leave space for explanation. Lastly, the point goes back to the high variability of MT proportions. If long bones are not a great predictor of body length, MTs and MCs are even worse, being one possible explanation to why published data does not match your estimate.
 
……
 
Another note, bones closer to the body (femur, humerus) scale more positively allometrically in terms of length than bones further away (ulna, tibia, etc.). Closer bones are more incorporated in the core body, and maybe that explains correlations. Lower bones could simply elongate for cursoriality purposes and not robusicity purposes in the taller species, explaining the negative allometry. Turner's table might support this. Epiphysis diameters also scaled quite negatively while shaft diameters positively.”


 
I know very well the individual variability of metapodials and the fact that they cannot be as accurate predictors of body size and mass epipodials and propodials. The foot anatomy and the load sharing among several small bones makes managing metacarpals and metatarsals quite tricky. Humerus and femur are generally the best limb long bone body mass predictors as they are single weight bearing bones. Radius and ulna for instance share loads and are generally not as good as humerus. Tibia is generally a predictor comparable or nearly comparable to the femur as the fibula takes a minor part of the total dynamic and static load in the distal hindlimb. No doubt that there is a significantly greater lever of uncertainty managing metapodials. Also a matter is estimating body size, a quite different and more complex matter is estimating body mass.
 
As far as I know there has never been an attempt to estimate body size and mass of the 192 mm MT3. Therefore I cannot see how published results contradict mine on this individual. The fist time the 192 mm appeared in published literature after the original report has been in Marciszak et al. (2014). I mentioned about this huge fossil in AVA on January 2012 without providing any detail on the original source and the kind of bone it was. Body size estimates of fossil lions found in literature are based on other bones and not on the 192 mm MT3. You assume any scientist knows any bone at any time of publication which is far from being true. Fossil felid body size estimates are traditionally generally simplified or relatively simplified and I found flaws in some of them. Ten years I went significantly more in depth and complexity in body size and mass estimates and although there is always room for inaccuracies and mistakes I trust my models more then anything else.
 
Make sure I have a voluminous database suited for the purposes of my studies, I accounted for any allometric phenomena and anything is done at professional level within the theory I am aware and the database I have. I have studied allometric scaling and allometric patterns very much in depth and since long time.
 
I estimate the straight head-and-body length for the 192 mm MT3 Cromerian lion to be most likely around 2500 mm. Obviously the level of uncertainty for a metapodial makes the possible range quite wide and depending by the model and confidence level on a statistical basis it could roughly be as low as 2300 mm or lower and as high as 2700 mm, whose upper side I obviously retain it totally unrealistic in practise. Even accounting for a diminutive scenario the size margin of a Pleistocene lion 192 mm MT3 is very high, and there are several other lion fossils confirming the size of that individual was not a genuine outlier. Even considering 2400-2450 mm it would still be a very large individual.
 
In my opinion HBL_straight around 2500 mm is not an overestimate due to bias and is in line with my estimate of  2300-2350 mm for the 480 mm Ngandong tiger femur individual. It is not too difficult to closely assess it even without the approach as rigorous as possible that I use.
 
 

4)   Articular and greatest length
 
 
“Christiansen's humerus length actually included the entirety of the femur, under the assumption that the protruding spur of the distal humerus is articular as most definitions says, test from his images yourself. Femur, tibia, etc. articular and greatest lengths are also the same, the articular surfaces are at the official ends of such bones."
 
 
I insist that the definition and his definition of articular and greatest lengths are different and to be rigorous there is the need to apply articular length of humerus, femur and tibia and greatest length of ulna when using Christiansen & Harris (2005) database. By their definition the difference in the case of femur and tibia is small, not so small in the case of humerus.
 
The proximal point of the articular surface is in proximal most point of the caput humeri while that for the greatest length is the most proximal one between the greater tuberosity and the caput humeri. The distal humeral articular surface include the trochlea and the capitulum. The humeral articular length is the distance from the caput humeri to the trochlear notch. Because of the trochlea feature the resulting lengths are normally markedly different even if the caput humeri is the top most point of the proximal epiphysis.
 
The articular length of radius is the distance from the medial point of the head to the middle of the lunate surface or the shelf of the carpal articular surface while the greatest length include the whole styloid process and the most proximal point of the head.. Because of the styloid process being a notch it implicates as for the humeral trochlea a marked difference between the two lengths.
 
In the case of the femur the reference point in the proximal epiphysis is the most proximal point of the caput femuri while in the distal articular surface can be either the mid-point of the condyles or the mid-point of the trochlear surface. Even when considering the mid-point of the condyles for the definition of the distal articular point (as Christiansen & Harris, 2005, do) if either the distal condyles are not both levelled with respect of the axis transversal to the axial principal bone direction and/or the greater trochanter is higher then the caput femuri the articular length is smaller then the greatest length.
 
The articular length of tibia is the distance between the most proximal point of the medial talar trochlear articulation and the medial condyle point.
 
I have both measurements of many different bones of many different carnivores species and they are slightly different. If Christiansen (1999) switched from greatest length of humerus and femur to articular lengths in Christiansen & Harris (2005) it means that he clearly meant the two lengths are conceptually different and serve different purpose in principle although generally they are close in the case of femur and tibia. I can guarantee you that for Christiansen the two lengths are not the same although very close.
 
The greatest lengths of bones include processes that are not closely related to weight bearing surfaces but are related to out-in lever features serving the purpose to move limb extremities with either greater strength or greater speed. These processes are taxa related and get rid of their size improve correlation and prediction abilities of bone length to body mass.
 
In the specific case of the 480 mm femur it is difficult to judge the ratio of the articular length to the greatest length particularly in the the proximal extremity due to the likely distorted pictures and the inconsistencies of the two views. However from the distal extremity it appears that the mid-point of the condyles is consistently closer in the axial projection to the caput femori then the lower most point of the condyles. The top part of the proximal epiphysis can be either the caput femuri or the greater trochanter depending by the view of the two pictures. You can try to do it by yourself
 
 
The total articular width of the distal humerus and femur exclude the epicondyles. It is clearly stated in Christiansen & Harris (2005). The two widths have not exactly the same measurements even in felids.
                 
 
Conclusively we can argue that the systematic errors accounting for greatest length and epicondylar mediolateral diameters instead of articular lengths (except ulna) and articular width may produce small body mass overestimates in some cases when using database of Christiansen & Harris (2005) and not always significant overestimates, but whenever possible it would be better to use the correct measurements to obtain more realistic results.
 
 
 
5)   Pictures of the 480 mm tiger femur from Ngandong Pleistocene


I have never seen such an amount of thinning of a tiger femur diaphysis towards the proximal epiphysis as in the 480 mm pictured from Von Koenigsvald (1933). Both pictures appear to be likely distorted.
 
I agree with the 59 mm proximal sagittal diameter is unrealistic and has no consistency with any other measurement. However reconstruct the likely correct width measurements from those pictures assuming the length is the correct one and generating as a result such a high increase in tiger limb long bone robustness that has NO corroboration from any other tiger limb bone being a femur or any other major limb bone either from Pleistocene and Holocene is a speculative exercise that in my opinion goes beyond a realistic and sensible analysis.
 
On January 2012 in AVA I wrote I had analyzed tiger fossil remains from Ngandong and came to the conclusion of how many individuals were likely included among the remains. I considered 7 fossil remains and sexed 5 males and 2 females with no doubt as it is very much clear in my opinion. I have estimated body size and mass of all of them for a long time. Either I consider the male sample or the pooled sample of both sexes, when considering the average size and mass and the standard deviation removing the very large individual, it results that an individual of the size of the 480 mm femur (using VK measurements) has a probability to occur not higher then around 2% and as small as much less then 1%.
 
Another suggestion why the 500 kg estimate is totally unrealistic in my opinion. You know that a realistic ultimate body mass of the largest panthera felid and many carnivores can be retained as around 150 % of the average body mass of the same sex at the very best and in my opinion is actually less then that in most cases. Ultimate means exceptional among many hundreds as a minimum and possibly thousands of adult individuals of that sex. If you therefore obtained 500 kg, it means that you should obtain an average body mass of at least around 340 kg among hundreds/thousands of Ngandong adult tiger individuals  You do not have hundreds as you have only 5 of them. Therefore the average body mass on a statistical basis should be much closer to the highest body mass. Perhaps 400 kg? I suggest you to never loose the sense of reality and the big picture.
 
In my case I have best estimates of average body mass of those 5 males between 245 kg and 250 kg and somewhat over 135 kg for those 2 females with the heaviest male (the 480 mm femur of course) around 315 kg. I definitely stick with my figures although I do not rule out the 480 mm femur individual could have been somewhat heavier (but as you can see my body mass estimates are always conservative even for the fossil lions, Smilodon and other extinct carnivores).
 
I would never dare to write a scientific paper with all the assumptions you made based on the length being the correct one, a quite unusual proximal AP diameter and generating a bone robustness on the basis of a distorted picture you cannot have a precise way to fix. This presumed robustness has no corroboration with any other Pleistocene and Holocene propodials and epipodials (major limb long bones) and come out with a 500 kg Pleistocene tiger particularly among 7 individuals only. When I posted the picture of that very massive brown bear from Alaska Peninsula taken in the Spring it was not only to joke a bit. It was to call to the reality because a brown bear that massive at a straight HBL length around 2300-2350 mm is not going to scale unrealistic weights of 600-700 kg in the Spring, but much likely no more then 500 kg. I am aware of only very few reliable and accurate Spring weights of brown bears in excess of 500 kg and these kind of weights are rather exceptional even in Kodiak Archipelago, Alaska Peninsula and Kamchatka. How you can conceive a panthera felid like that I have no idea.
 
Given the exceptional size of the 480 mm femur among the very few unearthed remains compared to the others the only way to get rid of any doubt is to find that femur and re-measure it. Whatever the measurement would be I personally can very hardly justify weights of 450 kg and more among panthera felids unless a bone would prove to be absolutely huge in size as a panthera felid cannot have the build of that massive brown bear I posted.

 
 
6)   My Database

 
“if you could please respond to our's as well. Especially, what is your mathematical model, as based on your Crater example, it seems more prone to interpretation than regression. Again, there is no way giving this general information can hurt, especially, as it looks to be, there is no expectations of getting anything published. You must admit, a large portion of the data you have found, as in the case of all of our members here, has come from this community. Collectively, posters have put the entirety of sources together and have all corners covered.”
 
 
Feel free to believe I just interpret things and do not rely on complex mathematical models and extensive database. On my side I do instead believe that matters in a web community are nearly always treated quite superficially, lacking a lot of theroretical background in many areas and with much insufficient data apart from hunting records of tiger weights and lengths in AVA and this website and to a lesser extent of those of a few other felids. I did however read some posters showing good knowledge in several areas in the months I spent in the community over the last 11 years.
 
The voluminous amount of material and the database I have collected have been very nearly entirely done with my own effort and research only over the last 20 years (and I mean more then 95%) and I can guarantee you that it has been a very big effort and very much time consuming. In the last 3 years I have to notice that I lost some pace in keeping it updated in the topics we are discussing in this community due to a number of reasons. I am however try now to go back to normal.

The fact that you can assume a large portion of the data I have come from this or any other web community make me think you have not yet realized how big can become a very large personal professional library and database. I have both and good links in the zoology and palaeontology professional community for reasons I am not interested to disclose. I hate to highlight things about myself and get personal, but who is telling you this is the one who posted in AVA many scientific and hunting records of lions and tigers back in early 2004 that nobody in the community knew about, data that are now very popular but that at that time were not. Who is telling you this is who privately received in my email box the Kerley et al. (2005) and Slaght et al. (2005) papers not later then early 2007 while no web community knew anything about those papers and data for likely more then another couple of years. Who is telling toy this was who first talked in January 2012 about an absolutely huge Pleistocene lion fossil remain never mentioned in scientific literature after the first original report of 23 years ago and that after 2 years has been finally mentioned in a peer-reviewed scientific paper. May be I am aware now of things the community will not know about before a few years.
 
At your age and still being a university student I also had probably not a fully clear idea what is a professional library and database, but with time I realized it and build one. Unfortunately there are always areas that need improvements in a process that never ends as I always would like to have more and more data to rely with even more confidence in my results. You are on the way to make a career in biology so I am totally confidence you will get to a professional level in all areas you need to. At that point may be we will meet, take a beer together and discuss privately of many topics I do not discuss in a web under the name of WaveRiders unless they have been covered by published research and these topics are being discussed.
 
I have been a quite irregular poster and reader since I joined the community in early 2004, earlier then any of you who are around here by this time but perhaps a very few exceptions. This is the third time interval spanning in total no more then 6 or 7 months so far in which I have been involved. I definitely want to say that for the benefits I received, and I definitely did benefit for a few things no doubt about it, I am grateful to those guys provide those info. Very much unfortunately the very most of those guys do not appear to be around here and around in general any more. At present time I am grateful to @peter as without a doubt he showed some old historical books on tigers I was not aware. Being present in the community and contribute for the months I did over the last 11 years has been for me a way to repay the community and I believe I have done it. Even this third period is a fruit of unusual circumstances of my life. I have no idea if my involvement can last much beyond this time when things will go back to normal at some point. I believe it will also depend from the level of discussions, the topics and how they are afforded.
 
The points I raised were not to compare my models with yours. Forget my estimates if you want as I did not say they must for sure the correct ones. I stated they are the ones I personally trust more, even more then those from Christiansen, but this it is up to me.
 
My critical analyses has been based to what you showed you have done without comparing it to what I did many years ago with little refinements since then and only minor updates as I have basically frozen my studies in these topics for a few years. I am now focusing my attention mostly in quite different areas. If my words have a weight they have for how I discuss your models, not how I have done mine or what I took into account.
 
In our discussion there is one major point and a minor one.
 
The major point is that in my opinion there is absolutely no way a 480 mm Pleistocene tiger femur can realistically generate a body mass of 450-500 kg and I share the same opinion of Christiansen while you seem to follow those of Hertler and Volmer, who are for sure nice and kind ladies and good researchers, but for their Pleistocene tiger weight estimates that I firmly reject.
 
The minor point is that in my opinion the Cromerian 192 mm MT3 is the largest felid individual ever existed and possibly even the heaviest one (as an individual) as the heaviest Smilodon populator in my very large database is likely to weigh around 370-380 kg according to my estimates. I first stated this in January 2012 in AVA. Several years before I had finally let Argant notice my feeling with that bone in a discussion we had and Jacqueline Argant confirmed me in writing she had no issue about that measurement avoiding me to ask them I would like to re-measure it. I also asked about another MT3 appearing to be as a different individual missing the distal epiphyses and I was confirmed of a length estimate at ca. 190 mm. Finally and with my great relief in late 2013/2014 Marciszak et al. (2014) stated the 192 mm MT3 had an incredible length. Have you ever heard in a peer-reviewed palaeontology publications of recent years to define a felid bone of  i n c r e d i b l e size? Incredible may mean hardly credible but it does not seem the case for that small piece of bone apparently actually measuring 192 mm.
 
 
                               WaveRiders
 

  Reply