The Cave Lion (Panthera spelaea and Panthera fossilis)

[Polar]

From Ursus Arctos on Carnivora, Bengal Tiger vs Smilodon fatalis:

Quote:The study uses a ratio of lower jaw strength for absorbing forces from biting down ("Zx") to lower jaw strength for resisting torsional stresses (i.e. struggling prey) ("Zy"). A high Zx/Zy ratio shows either:

1) The prey was strongly secured by strong forelimbs before the killing bite was made

2) The prey was strongly secured by a group before a killing bite was made

3) Some combination of both

Some Zx/Zy ratios at the canines from this and another study by the same author:

Gray Wolf: 0.90

Lion: 1.25

Tiger: 1.35

Leopard: 1.37

Jaguar: 1.43

Cougar: 1.46

Clouded Leopard: 1.83

American Lion: 1.84

Smilodon Fatalis: 1.89

Smilodon Populator: 2.49

Therrien argues below that the american lion had much stronger forelimbs than modern lions and could likely restain prey securely. He also argues that small groups could have hunted together as well.

The Zx/Zycanine value of Panthera atrox (1.84; Fig. 5)
is much higher than that of other large felids and similar
to Neofelis nebulosa, indicating that dorsoventral stresses
prevailed in the symphyseal region and that labiolingual
and torsional stresses exerted by struggling prey were
relatively lower. While it is generally agreed that the large
body size of Panthera atrox allowed it to tackle very
large herbivores, such as bison, horses, ground sloths,
camels, and proboscideans (e.g. Kurt´en & Anderson,
1980; Harris, 1992; Anyonge, 1993), it seems paradoxical
for this Pleistocene predator to have experienced lower
torsional stresses than by extant lions that hunt smaller
prey (Schaller, 1972). Although extant felids use their
forelimbs and claws to restrain prey (Gonyea&Ashworth,
1975), their jaws must still be able to remain locked on the
neck or muzzle of prey and withstand the unpredictable
stresses induced as prey struggle to escape. If Panthera
atrox were a predator of large herbivores, one would
expect it to have Zx/Zycanine values similar to, or even
lower than, those of extant lions. Claw and tooth marks
left on a Pleistocene steppe bison mummy (Bison priscus;
M. L. Guthrie, 1988; R. D. Guthrie, 1990) suggest that
Panthera atrox adopted killing techniques similar to
those used by modern lions. However, Anyonge (1996)
has shown that the cross-sectional geometric properties
(i.e. bending strength) of the limbs of Panthera atrox,
particularly of the humerus, were much greater than
those of the extant lion, being closer to those of the
brown bear, Ursus arctos. In other words, the extinct
lion had much stronger forelimbs than an extant lion
of similar body size. Therefore, large prey could have
been primarily subdued and restrained by the extremely
powerful forelimbs of Panthera atrox, which would have
greatly reduced stresses on the mandible during the
canine bite. Furthermore, because the Zx/Zycanine values
of Panthera atrox are so high, it is possible that cooperative
hunting may have been common practice in that species,
where one or a few individuals would have restrained
a large herbivore while another delivered the canine
killing bite. Indeed, the high degree of cephalization
observed in Panthera atrox (Kurt´en & Anderson, 1980),
the claw and tooth marks left on a bison mummy, and
native American cave paintings (M. L. Guthrie, 1988;
R. D. Guthrie, 1990) suggest that the extinct lion
may have hunted in small groups of two or three
individuals, rather than in a pride. This possibility is
further supported by the size distribution of Panthera
atrox individuals in the Rancho La Brea deposits, which
indicates that the extinct lion did not form prides as
modern lions do but may have hunted in pairs or alone
(Jefferson, 1992).

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