Freak Felids - A Discussion of History's Largest Felines

[tigerluver]

The "Amur" tiger of the Late Pleistocene
 
This will be a summary and analysis of the paper attached in my last post by Baryshnikov (2016).
 
The tiger bones in the study are around 40,000 years old. That puts them in the late Pleistocene, and in one of the warmer phases. These are probably the first official tiger bones to be found furthest north, essentially in the Amur tiger's modern range. 

*This image is copyright of its original author

So for starters, the theory many cite as the tiger expanding up north starting 10,000 years is completely debunked. Rather, Baryshnikov theorizes there were at least 2 waves of migration, and one of those was 10,000 years ago. A lesson here is that gene chronology still needs a lot of work. 
 
Extensive morphological analysis is difficult as there are not many complete bones and the mostly complete mandible we have is of a subadult and is not representative of the adult form. Baryshnikov found the dental characteristic of this sample to be the same as those found in Wahnsien (600-800 kya earlier) and other fossil tigers, ignoring size. The author went on to conclude a few slight teeth morphology differences that are not too significant as they fall within the range of intraspecific variation.

Looking at the mandibles myself, the subadult mandible of 204 mm (like 210 mm complete) has very large dentition. However, the other mandibles who would be somewhat larger than the subadult mandible have smaller teeth. Therefore, the subadult teeth to mandible proportions are likely a product of age rather than species traits. The other two mandibles are of adults and indicate that similar to the larger tiger subspecies and the Sunda prehistoric species (modern Sunda species show the opposite trend), this early "Amur" tiger had small teeth for its skull. 

Postcranial remains show a tiger of average robusticity. The metapodials that were uniquely wide in the Wahnsien tiger are of slightly above average to average thickness in the newer sample. It seems by 40 kya the tiger had its more slender modern form for that most part.

Size-wise, even though the sample is most composed of females according to Baryshnikov, most specimens are under 200 kg. There is a larger calcaneus that may be of 250-260 kg specimen. The cave lions sharing eastern Russia with this tiger seems to be about the same size, interestingly probably the smallest cave lion population I've examined (perhaps the UK population of cave lions was of similar size). The giant cave lions were off to the west of Russia, between the Urals and Germany. Even if the cave lions in this area were slightly larger (considering how many <170 kg tigers are in the new sample), the niche between the tiger and cave lion likely overlapped to beyond sustainable levels.


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