Comments thread for "In the footprints of Smilodon populator"

[tigerluver]

This is the comments thread for "In the footprints of Smilodon populator". Please post any questions and comments regarding the topic of the article here. Reply

[peter]

Interesting post on Smilodon populator. Here's a few questions on size, hunting ability, social life and evolution.

Print size

The print of the front paws of Smilodon populator had a width of 17,6 cm. and a length of 19,2 cm. Based on the shape of the prints of the front paw, chances are they were left by a male. Although large, the width of the 'heel' was 10,0-11,0 cm. The 'heel width' of adult male Amur tigers, for comparison, ranges between 9,5-12,5 cm. A male Amur tiger with a 'heel width' of 11,0-12,0 cm. is 180-210 kg. Males leaving a print with a 'heel width' of 12,5 cm. and over are heavier.

Prints left by tigers in northern India can be even larger. Here's two photographs of prints of large Indian tigers.

The first print was left by an exceptional tiger (Bengt Berg, 'Meine Jagd nach dem Einhorn', Frankfurt, 1933, pp. pp. 169-189) near Bhutan. According to Berg, that tiger was quite a bit larger than the heaviest (565 pounds) he had shot in India:

*This image is copyright of its original author

This is a photograph of a print left by a tiger in Rajaji. The prints seem as large as those left by the tiger mentioned above. In northern India and Nepal, large male tigers can exceed 600 pounds:

*This image is copyright of its original author

  

Most of us assume Late Pleistocene big cats like Smilodon populator, compared to today's big cats, were in a different class, but the prints found in Argentina are no larger than those left by large male tigers in India and Russia today. Furthermore, the hind paws of today's big cats are larger. Is there, apart from the prints discussed, more evidence that Smilodon was exceptional in size? Anything known about subspecies? 

Hunting ability

The prints of Smilodon found in Argentina strongly suggest this cat was frontheavy, which would have affected the way it moved. The prints also suggest Smilodon was partially or completely plantigrade. This would have affected the athletic performance.

Today's big cats are digitgrade. Apart from lions, they are ambush hunters able to take down herbivores several times their own weight. Anything known on the ability of Smilodon in this department?

Social life

A cat as big as Smilodon populator would have needed quite a bit of energy. As they, most probably, lacked the speed and athletic ability of today's big cats, the question is how they prevented seasonal energy deficits. 

Social hunters could be able to prevent problems in the food department by cooperation, but robustness and numbers would have enabled Smilodon to rob solitary hunters as well. Anything known on how they hunted?

Evolution

Every time I read a book or article in which Pleistocene big cats featured, I sensed the presence of today's big cats. My guess is they co-existed for quite some time. The situation changed when conditions changed. Maybe climate change resulted in a different distribution of large herbivores in the Late Pleistocene and maybe extra-large herbivores disappeared as a result of a shortage of food and pressure of humans. This would have affected hunters like Smilodon as well, whereas today's big cats could have been more adaptable. 

It's known Late Pleistocene lions adapted to different conditions by losing size first (referring to central and northeastern Russia) and following large herbivores to southwestern Asia later, enabling smaller solitary hunters to take over and to develop in size. Anything known on changing conditions in the Americas and the consequences for herbivores and hunters like Smilodon populator?

Would you agree with the conclusion that Smilodon was not enough cat to compete with today's big cats and not enough bear to compete with bears when large herbivores disappeared? Reply