Saber-toothed tigers are a side branch of the evolution of big cats, living in the Pleistocene-Holocene period 3 million to 15,000 years ago, and spent nearly 3 million years with evolving human ancestors. Saber-toothed tigers have a pair of huge canine teeth, half a foot long, hence the name. Saber-toothed tigers hunt large herbivores. The extinction of the saber-toothed tiger is closely related to the extinction of the mastodon. The Labrea Farm in downtown Los Angeles is one of the most unusual fossil sites in the world, and more than 2,000 have been restored, making the saber-toothed tiger the most well-known prehistoric cat.
Phobes are an extinct group of hieroglyphic proboscis orders that lived from the mid-Miocene to the early Pleistocene. Male dinosaurs are generally close to 5 meters tall at the shoulders and are estimated to weigh more than 15.6 tons. The upper jaw has no fangs, the lower jaw has a pair of large downward curved fangs. White teeth are characterized by 2-3 simple transverse spines, which are used to cut rods, and the corresponding biting action is common to most other more primitive proboscis orders. It is found in Asia, Africa and Europe. Adrienne Mayo points out that the fossils of dinosaurs found in Greece unravel the secrets of ancient giant creatures.
Giant short-faced bears belong to the spectacled bear subfamily derived from the New World. The earliest members of the spectacle bear subfamily were Pionarctos, Texas, which lived in the Miocene (21-2 million years ago). It is the ancestor of the ursiforman and the present-day spectacled bear. Although little is known about the early history of the ursidian, it was later widely distributed in North and South America during the Glacial Period of Kansa 800,000 years ago. In addition to the large mouth full of sharp teeth, the most prominent feature of the giant short-faced bear is that it has long limbs, when they usually walk, the back is about 1.7 meters from the ground, and when it stands up with its hind limbs, it is more than 4.3 meters, and the largest short-faced bear fossil found in North America is 4.3 meters high when standing.
The lidont originated in the Permian, 252 million years ago. Carnivorous, shaped like a wolf, was the first animal to have canine teeth, which was an important breakthrough in the history of biological evolution, and many mammals later had similar fangs, they could easily tear apart the flesh, just like a hot metal knife sliding through the butter, it has a title "Permian wolf". The plesiosaur was a mammalian reptile that lived in the late Permian, living in the desert, with sharp teeth and superb running ability, and preferred to feed on the ancestors of turtles, the dragons.
The jawed pig is slightly larger than the ancient giant pig and the complete tooth pig, also known as the pig, which is an extremely large type of giant pig family. The shoulder height is more than 2 meters and the body length is more than 3 meters. They all have a pair of large, gruesome canine teeth, sharp premolars, and a long, frighteningly large mouth. But in fact, they originated from the same suborder as the real pig and the hippopotamus--- the order of paleodonts, and like the members of the giant pig family such as the toothless beast, they have become extinct. It lived in Nebraska in the Early Miocene West of the United States 21 million years ago, and ran on the prairie with the secondary horse, lima, small ancient camel, far-horned rhinoceros, Dafoe beast and so on at that time. A large number of fossil pig fossils have been found in inner Las California, probably due to drought causing these large men to flock to a dry riverbed and eventually die there.
Mammoth, meaning "underground dweller" in Tatar, originated in tropical Africa in the Pliocene and lived until the Holocene 3700 years ago. At the same time as African elephants and Asian elephants, they evolved from the common ancestor Akebono in Africa, and are sisterly with African elephants and Asian elephants. Most mammoths have no hair but are almost hairless like modern elephants, and the largest species, likely another prairie mammoth, is estimated to have only a few hairs on its body. The average size of mammoths is smaller than that of dinosaurs and saber-toothed elephants, so it is not the largest ancient elephant, but it is the most famous. It is tall and strong, with stout legs, four toes on its feet, a particularly large head, and a pair of curved front teeth growing out of its mouth.
There have long been two speculations about the cause of mammoth extinction: the climate extinction theory and the human slaughter leading to extinction. To resolve this controversy, an American archaeological team examined both theories. They reasoned that if human hunting led to the extinction of mammoths, then in a particular region, the mammoth's extinction time should coincide with the time when humans entered the area. And if mammoths went extinct due to climate change, then in a given region, mammoths should coexist with humans and go extinct only after climate change. Different species of mammoths also have different causes of extinction, the monarch mammoth became extinct due to the invasion of true mammoths into North America and lost their ecological niche, and the Colombian mammoth is likely to become extinct due to climate change. The cause of the extinction of the true mammoth is most likely due to human hunting.