Post by OldGreenVulture on Jun 17, 2019 8:07:52 GMT
Morphology
The different groups of saber-toothed cats evolved their saber-toothed characteristics entirely independently. They are most known for having maxillary canines which extended down from the mouth even when the mouth was closed. Saber-toothed cats were generally more robust than today's cats and were quite bear-like in build. They were believed to be excellent hunters and hunted animals such as sloths, mammoths, and other large prey. Evidence from the numbers found at La Brea Tar Pits suggests that Smilodon, like modern lions, was a social carnivore.
The first saber-tooths to appear were non-mammalian synapsids, such as the gorgonopsids; they were one of the first groups of animals within synapsida to experience the specialization of sabre teeth, and many had long canines. Some had two pairs of upper canines with two jutting down from each side, but most had one pair of upper extreme canines. Because of their primitiveness, they are extremely easy to tell from machairodonts. Several defining characteristics are a lack of a coronoid process, many sharp "premolars" more akin to pegs than scissors, and very long skulls.
The second appearance is in Deltatheroida, a lineage of Cretaceous metatherians. At least one genus, Lotheridium, possessed long canines, and given both the predatory habits of the clade as well as the generally incomplete material, this may have been a more widespread adaptation.[9]
The third appearance of long canines is Thylacosmilus, which is the most distinctive of the saber-tooth mammals and is also easy to tell apart. It differs from machairodonts in possessing a very prominent flange and a tooth that is triangular in cross section. The root of the canines is more prominent than in machairodonts and a true sagittal crest is absent.
The fourth instance of saber-teeth is from the clade Oxyaenidae. The small and slender Machaeroides bore canines that were thinner than in the average machairodont. Its muzzle was longer and narrower.
The fifth saber-tooth appearance is the ancient family of carnivores, the nimravids. Both groups have short skulls with tall sagittal crests, and their general skull shape is very similar. Some have distinctive flanges, and some have none at all, so this confuses the matter further. Machairodonts were almost always bigger, though, and their canines were longer and more stout for the most part, but exceptions do appear.
The sixth appearance is the barbourofelids. These carnivores are very closely related to actual cats. The best-known barbourofelid is Barbourofelis, which differs from most machairodonts by having a much heavier and more stout mandible, smaller orbits, massive and almost knobby flanges, and canines that are farther back. The average machairodont had well-developed incisors, but barbourofelids were more extreme.
The seventh and last of the saber-tooth group to evolve were the machairodonts themselves.
en.wikipedia.org/wiki/Saber-toothed_cat
The different groups of saber-toothed cats evolved their saber-toothed characteristics entirely independently. They are most known for having maxillary canines which extended down from the mouth even when the mouth was closed. Saber-toothed cats were generally more robust than today's cats and were quite bear-like in build. They were believed to be excellent hunters and hunted animals such as sloths, mammoths, and other large prey. Evidence from the numbers found at La Brea Tar Pits suggests that Smilodon, like modern lions, was a social carnivore.
The first saber-tooths to appear were non-mammalian synapsids, such as the gorgonopsids; they were one of the first groups of animals within synapsida to experience the specialization of sabre teeth, and many had long canines. Some had two pairs of upper canines with two jutting down from each side, but most had one pair of upper extreme canines. Because of their primitiveness, they are extremely easy to tell from machairodonts. Several defining characteristics are a lack of a coronoid process, many sharp "premolars" more akin to pegs than scissors, and very long skulls.
The second appearance is in Deltatheroida, a lineage of Cretaceous metatherians. At least one genus, Lotheridium, possessed long canines, and given both the predatory habits of the clade as well as the generally incomplete material, this may have been a more widespread adaptation.[9]
The third appearance of long canines is Thylacosmilus, which is the most distinctive of the saber-tooth mammals and is also easy to tell apart. It differs from machairodonts in possessing a very prominent flange and a tooth that is triangular in cross section. The root of the canines is more prominent than in machairodonts and a true sagittal crest is absent.
The fourth instance of saber-teeth is from the clade Oxyaenidae. The small and slender Machaeroides bore canines that were thinner than in the average machairodont. Its muzzle was longer and narrower.
The fifth saber-tooth appearance is the ancient family of carnivores, the nimravids. Both groups have short skulls with tall sagittal crests, and their general skull shape is very similar. Some have distinctive flanges, and some have none at all, so this confuses the matter further. Machairodonts were almost always bigger, though, and their canines were longer and more stout for the most part, but exceptions do appear.
The sixth appearance is the barbourofelids. These carnivores are very closely related to actual cats. The best-known barbourofelid is Barbourofelis, which differs from most machairodonts by having a much heavier and more stout mandible, smaller orbits, massive and almost knobby flanges, and canines that are farther back. The average machairodont had well-developed incisors, but barbourofelids were more extreme.
The seventh and last of the saber-tooth group to evolve were the machairodonts themselves.
en.wikipedia.org/wiki/Saber-toothed_cat