reddhole

 

Source: Per Christiansen and John M. Harris, "Body Size of Smilodon", Journal of Morphology: 266: P 369-384, 2005

Here is the abstract:

ABSTRACT The body masses of the three large sabertoothed
machairodontines, Smilodon gracilis, S. fatalis,
and S. populator, were estimated on the basis of 36 osteological
variables from the appendicular skeleton of extant
felids. A new model is introduced that takes the
reliability of the predictor equations into account, since
mass estimates are more reliable when computed from
multiple variables per bone. At a body mass range of
55–100 kg, S. gracilis was comparable in size to extant
jaguars, and S. fatalis was found to be somewhat lighter
than previously assumed, with a body mass range of 160–
280 kg, similar to that of the largest extant felid, the
Siberian tiger. Smilodon populator was substantially
heavier and larger than any extant felid, with a body mass
range of 220–360 kg. Particularly large specimens of S.
populator almost certainly exceeded 400 kg in body mass.
The differences from previous estimates are most likely
caused by differences in the databases used for mass estimation.

Below is a discussion of the weight ranges of the Smilodon species:

The included specimens of Smilodon, although
showing some size-variation and including large
specimens, are not among the largest known (see,
e.g., Merriam and Stock, 1932; Kurte´n and Werdelin,
1990). Accordingly, the extreme upper size
ranges of Smilodon are probably not represented in
the current study and, since unusually large specimens
in extant mammals are always rare, it is unlikely
that such specimens will ever be found in the
fossil record. Among extant mammals, at least the
larger species, some unusually large specimens significantly
exceed the upper size range of normal
individuals (see, e.g., Wood, 1976; Nowak, 1991;
Christiansen, 1999a, 2004), a pattern also present in
felids (Sunquist and Sunquist, 2002).

Although males of both lions and tigers exceeding
300 kg in body mass have been shot (Wood, 1976;
Sunquist and Sunquist, 2002), this is well outside
the normal size range of even very large males (Fig.
5), and adult Siberian tiger males usually range
from 220–260 kg (Sunquist and Sunquist, 2002), in
accord with the sizes of the three specimens used in
the present analysis (Table 1; Appendix A). Accordingly,
unusually large specimens of Smilodon may
well have significantly exceeded the body mass
ranges reported here also. Accordingly, S. gracilis
almost certainly, on occasion, exceeded 130 kg (Fig.
5), as in extant jaguars (Nowak, 1991; Sunquist and
Sunquist, 2002). Particularly large S. fatalis males
may well have reached a body mass of around 350 kg
(Fig. 5), if not more, but unlike Anyonge (1993), we
suggest that this value is best regarded as an outlier
to the normal size range of this species.

Smilodon populator is clearly one of the largest
felids ever discovered, rivaled only by the giant
Pleistocene North American lion (Panthera atrox;
see Merriam and Stock, 1932; Anyonge, 1993;
Turner and Anton, 1997), and even normal-sized
individuals are predicted to have rivaled world
record Siberian tiger males (see Wood, 1976; Nowak,
1991; Sunquist and Sunquist, 2002). There is every
reason to suppose that unusually large S. populator
males exceeded 400 kg in body mass, perhaps significantly
so. This would effectively remove S. populator
from the size distribution of extant felids (Fig.
5).

Here is a comparison of the normal weight ranges and the weights of exceptionally large individuals of extant big cats and the the three Smilodon species:

Megafelis fatalis

 

Smilodon's Mane

:Question:
How likely is it that Smilodon and other saber-toothed cats had manes like modern-day lions? I know that male lions use their manes for display against other males and rival predators, and in addition to having manes, male lions differ from females in being larger. But I read that although there is evidence of Smilodon living in groups like lions, both males and females were supposedly about the same size. Is this true? Is there any evidence of sexual dimorphism in Smilodon? If not, does that indicate that male Smilodon were maneless? Could both males and females have had manes? Or could male Smilodon have just had a small ruff around the head and neck like a male tiger?


:Answer:
According to Yamaguchi et al. (2004), the mane of male lions is "a secondary sexual character thought to have evolved through sexual selection, possibly relating to the evolution of group-living of reproductively active females. The mane is thought to be visually intimidating in contests between males while serving as body armour during fights, and also to have a function in attracting females."

On the other hand, cave paintings of late Pleistocene European cave lions are clearly maneless even in an animal with a clearly-depicted scrotum. This is quite strong evidence that male European cave lions did not possess manes and it is likely that the manes appeared more recently in modern lion subspecies.

With regards to Smilodon there is no evidence to suggest that male individuals were maned. Social living in Smilodon have been inferred but mostly from circumstantial evidences. Even if Smilodon was indeed a social animal, group-living does not immediately equate to the presence of maned males. Also, as the evolution of the mane seems to be a unique feature in modern lions, regardless of whether Smilodon was social or solitary, it is safer to say that Smilodon was maneless like other large cats, including the late Pleistocene European cave lion.

Manabu Sakamoto

http://www.askabiologist.org.uk/experts/manabusakamoto

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Although manes are unusual in cats (being the product of runaway selection pressures) ruffs are rather common in cool temperate species. Obviously ruffs insulate the throat, reducing heat loss where large blood vessels pass close to the skin.

I would doubt that Smilodon had a mane, but there is a reasonable chance it would have had a ruff.

Paolo Viscardi

http://www.askabiologist.org.uk/experts/paoloviscardi

From Ask Biologist
http://www.askabiologist.org.uk

Mack

 

Not as good as some other reconstructions but still better then some others

Quote:

 

From Taipan/Reddhole: Source: Therrien; "Mandibular Profiles of Extant Carnivores and Implications for the Feeding Behavior of Extinct Predators"; Journal of Zoology: 267: P 249-270; 2005

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. [/size]

Quote:

 

The face of Miller's Machairodont

American paleontologist George Miller set forth a set of features not previously thought of in the soft tissues of machairodonts, specifically Smilodon.

The first change he suggested in the appearance of machairodonts were lower ears, or rather the illusion of lower ears due to the higher sagittal crest. This claim has been generally discarded due to its unique nature: no other modern carnivores have these low set ears for this reason, but alternatively, no other carnivore has such a sagittal crest. For this reason, the positioning of the pinna, or outer ear, along with fur color, are dependent upon the individual doing the reconstruction. Large or small, pointed or rounded, high or low, fossils do not record these characteristics, leaving them up to interpretation.


Miller's first change: low set ears, as seen with the African honey badger, Mellivora.

Miller also suggested a pug-like nose. Aside from the pug and similar dogs, no modern carnivore exhibits a pug-nose. The relatively low distribution of the pug nose has resulted in it being generally ignored. Miller's rationale is based upon the retraction of Smilodon nasal bones. Criticism of Miller's theory compares the nasal bones of lions and tigers. Lions, when compared to tigers, also have strongly retracted nasal bones, but a lion's rhinarium, or external nose, is no more retracted than the tiger's. Thus the pug-nose of Smilodon proposed by Miller has little evidence in the physical structures of comparable animals.


Miller's second change: a pug nose, as seen with a domestic dog, the pug, Canis lupus familaris.

The third idea proposed is the elongation of the lips by 50 percent. While his other hypotheses have been largely discarded, the last is used significantly in modern depictions. Miller argues that longer lips allows the greater elasticity needed for biting prey with a wider gape. Although this argument has been rebuked strongly within the scientific community, it remains supported nevertheless by artists. Scientific criticism points out that the lips of modern cats, especially larger species, display incredible elasticity and the usual lip length would stretch suitably, despite the larger degree of opening. Regardless, reconstructions of Smilodon, Machairodus, and other species are shown with long lips, often resembling the jowls of large dogs.


Miller's third change: jowls, as seen with a domestic dog, the Boxer, Canis lupus familiaris.