The Smilodon are among the largest felids, the heaviest specimens of this massively built carnivore may have exceeded 400 kg (880 lb).
A Smilodon had a short tail, powerful legs, muscular neck and long canines. Despite being around the same size as a tiger or lion, Smilodon was more robustly built, comparable to a bear.
It shown to scale to demonstrate the compact muscular buildA fully-grown Smilodon weighed approximately 55 to 360 kg (120 to 790 lb), depending on species.
Smilodon had relatively shorter and more massive limbs than other felines. It had well developed flexors and extensors in its forepaws, which enabled it to pull down large prey. The back limbs had powerfully built adductor muscles which might have helped the cat's stability when wrestling with prey. Its claws were retractable.
Teeth and jaws
They are the longest canines of the saber-toothed cats at about 28 cm (11 in) long in the largest species Smilodon populator. They were probably built more for stabbing than slashing. Despite being more powerfully built than other large cats, Smilodon actually had a weaker bite. Modern big cats have more pronounced zygomatic arches, while Smilodon had smaller zygomatic arches which restricted the thickness and therefore power of the temporalis muscles, and thus reduced Smilodon’s bite force. Analysis of its narrow jaws indicates that it could produce a bite only a third as strong as that of a lion.There seems to a be a general rule that the saber-toothed cats with the largest canines had proportionally weaker bites. However, analyses of canine bending strength (the ability of the canine teeth to resist bending forces without breaking) and bite forces indicate that saber-toothed cats' teeth were stronger relative to the bite force than those of modern "big cats". In addition, Smilodon could open its jaws 120 degrees, whereas the lion can only open its jaws to 65 degrees.
Smilodon probably preyed on a wide variety of large game including bison, Megatherium, Aurochs, deer, American camels, horses and . As it is known for the saber-toothed cat Homotherium, Smilodon might have killed also juvenile mastodons and mammoths.
Smilodon called sabre-toothed cat or sabre-toothed tiger, is an extinct genus of the subfamily machairodontine saber-toothed cats endemic to North America and South America living from the Early Pleistocene through Lujanian stage of the Pleistocene epoch (1.8 mya—10,000 years ago), existing for approximately 1.790 milion years.