Smilodon,The Overpowered True King of the Big Cats !

[kevin]

The Sabertooth wasn't only stronger than other cats in the forelimbs but in the shoulders as well. The following comparison demonstrates how fatalis had relatively more powerful shoulders than American Lions :


Scapula Shape Index:[/u]
It's scapula width/forelimb length ratio.Higher score indicates greater muscle attachement on the shoulder joint as well as greater ability to make certain movements like full-functional upper extremity movement including protraction, retraction, elevation, depression, upward rotation,and downward rotation all else being equal.
S.Fatalis : 24%
P.Atrox : 21%
Edge : S.Fatalis
Scapula Length Index:[/u]
Scapula length divided by Forelimb length.Higher score Indicates exertion of greater force from the Forelimb.
S.Fatalis : 33%
P.Atrox : 30%
Edge : S.Fatalis
API:[/u]
Acromion process length/forelimb length.Higher score in this ratio increases attachment for the deltoid muscle.
S.Fatalis : 2%
P.Atrox : 2%
Edge : Draw
SMI:[/u]
Deltopectoral crest length divided by humerus length. Higher score Displays greater mechanical advantage of deltoid and pectoral muscles at the shoulder joint.
S.Fatalis : 64%
P.Atrox : 62%
Edge : S.Fatalis

References:[/u]

www.researchgate.net/publication/230843015_Postcranial_morphology_and_the_locomotor_habits_of_living_and_extinct_carnivores

academic.oup.com/zoolinnean/article/151/4/833/2607398

[kevin]

Confirming once again that Smilodon was a cat in a bear's body :


www.researchgate.net/p..._living_and_extinct_carnivores

[kevin]

In addition to having Stronger shoulders than Panthera Atrox, fatalis most likely owned a stronger chest as well due to its more robust and more curved ribs : 

www.google.co.ma/books/edition/The_Other_Saber_tooths/2GjhrKO9y74C?hl=fr 

[kevin]

Another feature Smilodon had in comparison to pantherines was its relatively shorter and more robust back :

cup.columbia.edu/book/the-big-cats-and-their-fossil-relatives/9780231102292#:~:text=In%20this%20beautifully%20illustrated%20natural,that%20of%20the%20fossil%20record.
Such feature helped Smilodon outwrestle large prey even more effectively than modern big cats do !

[kevin]

Relative humerus robusticity comparison between Smilodon Populator and Ursus Arctos ![/u][/size]

HRI: [/u]
It is humerus mediolateral diameter at mid-shaft/humerus length. Robust forelimb
bones protect the animal from violent stresses during grappling.
S.Populator : 11%
U.Arctos : 11%
Edge : Draw
HRI2:[/u]
It is humerus anteroposterior diameter at mid-shaft/humerus length. Robust forelimb
bones protect the animal from violent stresses during grappling.
S.Populator : 14%
U.Arctos : 12%
Edge : S.Populator
HCMI:[/u]
It is Humeral circumference/articular length Often-used variable in analyses of bone
strengths in locomotion. The higher the ratio is, the thicker the Humeral bone is.
S.Populator : 40%
U.Arctos : 34%
Edge : S.Populator

Overall :[/u] S.Populator

www.researchgate.net/publication/230843015_Postcranial_morphology_and_the_locomotor_habits_of_living_and_extinct_carnivores

www.researchgate.net/publication/20806549_Differential_scaling_of_the_long_bones_in_the_terrestrial_carnivora_and_other_mammals

www.researchgate.net/publication/7531697_Body_size_ofSmilodon_Mammalia_Felidae

bmcbiol.biomedcentral.com/articles/10.1186/1741-7007-10-60

www.jstor.org/stable/23735739

[kevin]

Relative humerus robusticity comparison between Smilodon Fatalis and Ursus Maritimus ![/u][/size]

HRI: [/u]
It is humerus mediolateral diameter at mid-shaft/humerus length. Robust forelimb
bones protect the animal from violent stresses during grappling.
S.Fatalis : 13%
U.Maritimus : 10%
Edge : S.Fatalis
HRI2:[/u]
It is humerus anteroposterior diameter at mid-shaft/humerus length. Robust forelimb bones protect the animal from violent stresses during grappling.
S.Fatalis : 15%
U.Maritimus : 12%
Edge : S.Fatalis
HCMI:[/u]
It is Humeral circumference/articular length Often-used variable in analyses of bone strengths in locomotion. The higher the ratio is, the thicker the Humeral bone is.
S.Fatalis : 34%
U.Maritimus : 32%
Edge : S.Fatalis

Overall :[/u] S.Fatalis

www.researchgate.net/publication/230843015_Postcranial_morphology_and_the_locomotor_habits_of_living_and_extinct_carnivores

www.researchgate.net/publication/20806549_Differential_scaling_of_the_long_bones_in_the_terrestrial_carnivora_and_other_mammals

academic.oup.com/zoolinnean/article/151/4/833/2607398

www.jstor.org/stable/23735739

[kevin]

Dirk-toothed cats such as Smilodon had limbs which were so stout they would actually made lion limbs seem gracile in comparison 😭 :

www.researchgate.net/publication/266753114_Felid_form_and_function

[kevin]

One study has the following to say :


pubmed.ncbi.nlm.nih.gov/18313908/

A higher score in robusticity index translates to having shorter, heavier trunks (i.e stronger back) which help improve the strength and stability of an animal. This is what we find when we compare Smilodon with Panthera cats and Bears using data from the above study :

Smilodon : 0,3865-n=2
Panthera : 0,2323-n=3
Bear : 0,3116-n=3

Although the sample size is small and most likely not conclusive,it appears that Smilodon onwed relatively Stronger backs than Pantherines and even Bears !

[kevin]

Smilodon gracilis, the smallest and least impressive of the Smilodon species, is still strong enough to compete with and even outscore several modern big cat species such as Jaguars and even some prehistoric cats such as dinictis felina in terms of relative forelimb robusticity (except for paw width) :


www.researchgate.net/publication/261974255_Morphological_convergence_of_the_prey-killing_arsenal_of_sabertooth_predators

P.s : lower score in BI is better

Note that the HRI score for fatalis is outdated as a later study from one of the authors gives an even higher score of 12,71% :

www.researchgate.net/publication/230843015_Postcranial_morphology_and_the_locomotor_habits_of_living_and_extinct_carnivores

[kevin]

Both the tiger and the puma look gracile in comparison to the Sabertooth. The modern lion doesn't fare much better. The American Lion does seem to somewhat rival fatalis in shaft robustness. It should still be kept in mind that the distal end is wider in fatalis than in Atrox, indicating greater muscle attachements in the former.

[kevin]

Morphological Forelimb Comparison Between Smilodon Fatalis And Arctodus Simus ![/u][/size]


Scapula Shape Index: [/u]
It's scapula width/forelimb length(humerus+radius) ratio.Higher score indicates greater muscle attachement on the shoulder joint as well as greater ability to make certain movements like full-functional upper extremity movement including protraction,retraction,elevation,depression,upward rotation,and downward rotation all else being equal.
S.Fatalis : 30%
A.Simus : 27%
Edge : S.Fatalis
Scapula Length Index: [/u]
Scapula length divided by forelimb length (humerus+radius). Higher score Indicates greater speed of movement via relative proportions of components of the proximal forelimb.
S.Fatalis : 41%
A.Simus : 36%
Edge : S.Fatalis
API: [/u]
Acromion process length/forelimb length(humerus+radius). Higher score in this ratio increases attachment for the deltoid muscle.
S.Fatalis : 3%
A.Simus : 6%
Edge : A.Simus
SMI: [/u]
Deltopectoral crest length divided by humerus length. Higher score Displays greater mechanical advantage of deltoid and pectoral muscles at the shoulder joint.
S.Fatalis : 64%
A.Simus : 56%
Edge : S.Fatalis
HRI: [/u]
It is humerus mediolateral diameter at mid-shaft/humerus length.Robust forelimb bones protect the animal from violent stresses during grappling.
S.Fatalis : 13%
A.Simus : 11%
Edge : S.Fatalis
HRI2: [/u]
It is humerus anteroposterior diameter at mid-shaft/humerus length. Robust forelimb bones protect the animal from violent stresses during grappling.
S.Fatalis : 15%
A.Simus : 13%
Edge : S.Fatalis
HCMI: [/u]
It is Humeral circumference/articular length Often-used variable in analyses of bone strengths in locomotion. The higher the ratio is, the thicker the Humeral bone is.
S.Fatalis: 34%
A.Simus : 32%
Edge : S.Fatalis
HEI: [/u]
The HEI index measures the relative size of wrist stabilizing muscles and well as several grasping muscles in area which facilitate prey grasping. These muscles also likely help stability, pushing, and agility when legs are on ground.
S.Fatalis : 33%
A.Simus : 32%
Edge : S.Fatalis
HTI: [/u]
It's Humeral trochlear length/Humeral length. Higher score increases muscle attachement on the elbow joint and allows for more ulnohumeral flexion and extension.
S.Fatalis : 21%
A.Simus : 23%
Edge : A.Simus
Brachial Index: [/u]
This measures radius length/humerus length. Lower scores in this ratio indicate greater forelimb muscle mechanical advantage and results in stronger muscles all else being equal.
S.Fatalis : 79%
A.Simus : 85%
Edge : S.Fatalis
Brachial Index 2: [/u]
This measures ulna length/humerus length. Lower scores in this ratio indicate greater forelimb muscle mechanical advantage and results in stronger muscles all else being equal.
S.Fatalis : 100%
A.Simus : 94%
Edge : A.Simus
RRI: [/u]
This measures radius mediolateral diameter at midshaft divided by radius length. As mentioned above for humerus robusticity, a robust radius resists stresses on bones during fights and increases resistance to bites to the forelimb.
S.Fatalis : 12%
A.Simus : 6%
Edge : S.Fatalis
RRI2: [/u]
This measures radius anteroposterior diameter at midshaft divided by radius length. As mentioned above for humerus robusticity, a robust radius resists stresses on bones during fights and increases resistance to bites to the forelimb.
S.Fatalis : 8%
A.Simus: 8%
Edge : Draw
OI: [/u]
This metrics estimates tricep muscle strength. High values indicate greater ability to push with arms all else being equal. This helps a grappling cat hold prey and also helps a canid push and knock down an opponent. In addition, higher values may indicate greater stability and ability to change direction in a fight.
S.Fatalis : 24%
A.Simus : 15%
Edge : S.Fatalis
URI: [/u]
It is ulna mediolateral diameter at mid-shaft/humerus length. As mentioned above for humerus and radius robusticity, Robust forelimb bones protect the animal from violent stresses during grappling.
S.Fatalis : 8%
A.Simus : 5%
Edge : S.Fatalis
URI2: [/u]
This measures ulna anteroposterior diameter at midshaft divided by ulna length. As mentioned above for humerus and radius robusticity, a robust ulna resists stresses on bones during fights and increases resistance to bites to the forelimb.
S.Fatalis : 12%
A.Simus : 9%
Edge : S.Fatalis




Studies Used for The Above Comparison : [/u][/size]






www.researchgate.net/publication/230843015_Postcranial_morphology_and_the_locomotor_habits_of_living_and_extinct_carnivores





pubmed.ncbi.nlm.nih.gov/28202470/#:~:text=In%20contrast%20to%20most%20other,force%20couples)%20to%20the%20ground.



www.semanticscholar.org/paper/What-size-were-Arctodus-simus-and-Ursus-spelaeus-Christiansen/14c1ecaa29bb88d8930fa543279937074628c946



www.semanticscholar.org/paper/Osteology-and-ecology-of-Megantereon-cultridens-a-%E2%80%93-Christiansen-Adolfssen/f5dd2b7f596ef6b84aff81281e97e6f7f75422a6





During the Pleistocene Epoch, Giant Short-Faced Bears lived alongside Sabertooth Cats. Nobody knows for sure if they ever fought, however this side by side comparison has demonstrated that overall, Smilodon had proportionally stronger shoulders as well as more robust and more muscular forelimbs.

[kevin]

It's important to mention that while it is possible to argue that Smilodon was stronger than a bear at size parity, it doesn't mean that one should support a 250 kg Sabertooth over a 450 kg or even a 350 kg bear in a fight. Size plays a significant role and one with a greater weight increase would need a greater increase in robusticity in order to support said weight increase. Best example is lion vs jaguar : The jaguar is pound for pound stronger than a lion however a 190 kg lion is undoubtedly stronger than a 110-120 kg jaguar due to the former needing more robust bones to support a 70-80 kg weight increase.

[kevin]

Relative shoulder power comparison between S.Fatalis and the modern jaguar :


Scapula Length Index :[/u]
Scapula length divided by Forelimb length (humerus +radius+metacarpal III).Higher score Indicates exertion of greater force from the Forelimb.
S.Fatalis : 35%
P.Onca : 34%
Edge : S.Fatalis
Glenoid Process Index :[/u]
Glenoid Process/scapula Length.Lower score Indicates greater shoulder mobility.
S.Fatalis : exact value unknown
P.Onca : exact value unknown

Edge : Draw
M.teres Major Index :[/u]
Higher score Indicates greater power for shoulder extension.
S.Fatalis : exact value unknown
P.Onca : exact value unknown

Edge : S.Fatalis
M.teres Major Index 2 :[/u]
Higher score Indicates greater power for shoulder extension.
S.Fatalis : 19%
P.Onca : 14%
Edge : S.Fatalis
GL/LI :[/u]
Lower score provides greater power and higher velocity to the Forelimb.
S.Fatalis : 242%
P.Onca : 268%
Edge : S.Fatalis
SMI :[/u]
Deltopectoral crest length divided by humerus length. Higher score Displays greater mechanical advantage of deltoid and pectoral muscles at the shoulder joint.
S.Fatalis : 64%
P.Onca : 55%
Edge : S.Fatalis


References:[/u]

www.researchgate.net/publication/230843015_Postcranial_morphology_and_the_locomotor_habits_of_living_and_extinct_carnivores

www.semanticscholar.org/paper/Osteology-and-ecology-of-Megantereon-cultridens-a-%E2%80%93-Christiansen-Adolfssen/f5dd2b7f596ef6b84aff81281e97e6f7f75422a6


publikationen.uni-tuebingen.de/xmlui/handle/10900/48480

Poor jaguar couldn't outscore Smilodon in just one indicator 😭. It just doesn't compare to the Sabertooth.

[kevin]

journals.plos.org/plosone/article?id=10.1371/journal.pone.0011412

It's also interesting to mention how the screenshot blantatly states that in terms of Forelimb strength, we have later Sabertooth species such as Smilodon>promeganteron ogigya>conical toothed cats such as lions,tigers,jaguars,pumas, leopards,cheetahs,snow leopards,clouded leopards etc.

[Hardcastle]

Jul 5, 2023 11:32:03 GMT kevin said:

How would Smilodon fatalis and Smilodon Populator fit in the following graph ?



When we divide ML humerus diameter by humerus length, we get 12,71% for Smilodon fatalis as per the latest dataset :
www.researchgate.net/publication/230843015_Postcranial_morphology_and_the_locomotor_habits_of_living_and_extinct_carnivores
And we get 11,4% for Smilodon Populator as per this study :
pubmed.ncbi.nlm.nih.gov/16235255/

According to these numbers, we conclude that both Sabertooth species outscored a large number of felid,canid,hyeanid,mustelid,and Ursid species with fatalis being at the very top alongside roman bulldogs and Populator being a worthy rival for sloth bears in relative humeral robusticity. Credit to Hardcastle for the graph.

It's high time I fix that graph, there's minor issues and confusions with the dogs, and while I'm at it I could add smilodons (fatalis and populator) and possibly dire wolves.