10 Extinct Prehistoric Mammals and Their Sizes – See How They Compared to Humans

As a blue life planet, Earth has nurtured countless species over its 460 million years of evolution, and some of these species have disappeared from Earth. Here are 10 extinct prehistoric mammals, through which you can understand their size and how they once existed. One, Upper CanineBody length 1.5 meters, shoulder height 0.9-1.1 meters, weight 80-130 kilograms. The Upper Canine is twice as big as the current gray wolf, with a powerful physique and unyielding group strength, making these terrifying animals a nightmare for many vegetarian animals in North America.Although the Upper Canine dominated for a while in the Middle-Late Eocene, with the global climate turning cold and dry in the Late Middle-Late Eocene to the Early Miocene, the Upper Canine also disappeared from the long history of Earth.Two, American Pseudo-LionFull length 4.5 meters, tail length 1.5 meters, shoulder height 0.9-1.3 meters, weight 200-500 kilograms. The American Pseudo-Lion was the second largest animal in North America during the Ice Age (20000 years), not only a giant in the American cat genus, but also the largest cat genus in the history of the Earth. The American Pseudo-Lion went extinct because the Ice Age ended and food was scarce.Three, Moni MouseFull length 3 meters, shoulder height 1.2-1.5 meters, weight 400-1100 kilograms. Unlike the familiar old mice, the Moni Mouse is an extinct giant mouse, with a body size like a bull, the largest rodent known to date, living about 400000 years ago in South America.Due to climate change making the habitat dry and other predators invading, the Moni Mouse was defeated in the fierce competition for survival, thus it went extinct.Four, South American Short-faced BearBody length 3.6 meters, shoulder height 1.8-2.0 meters, weight 980-2040 kilograms. Distributed in South America, surviving in the Early and Middle Pleistocene (200000 to 70000 years ago), it was the largest meat-eating animal on land at that time, and the largest mammalian meat-eating animal ever.As for the extinction of the South American Short-faced Bear, experts believe it was caused by the lack of large animals for food and the arrival of humans.Five, Great HorseShoulder height 2.1 meters, weight 1300 kilograms. The name 'Great Horse' is because its horns are very large, with a horn face width of 2.5 meters. The Great Horse lived from 300000 to 12000 years ago on the Eurasian continent, it is the largest horse, most famous in the Irish region, so it is also called Irish Elk.There is a theory that the Great Horse went extinct because it could not bear such large horns, but this theory has not been widely verified until 1974. Also, there is a saying that the Great Horse's extinction is due to the existence of humans and the reduction of its habitat. In short, the causes of the extinction of the Great Horse in a few places are multiple theories, but ultimately the disappearance on the Eurasian continent has no definitive answer.Six, Step-Climbing ApeStanding height over 3.0 meters, weight 560 kilograms. The Step-Climbing Ape lived in China, India and Vietnam from 100000 to 30000 years ago, it is a huge ape similar to a gorilla living on the ground, it is likely the largest ape. The Step-Climbing Ape was distributed in Asia. Because its fossils were found together with the extinct panda ancestors, it is estimated that it lived in bamboo forests. Most evidence points to the ape being herbivorous. Some scholars believe that the Step-Climbing Ape went extinct because it competed with humans.Seven, River HorseBody length 4.3 meters, shoulder height 2.1 meters, weight 3900 kilograms.The River Horse first appeared 180000 years ago, distributed in Europe, went extinct in the late Pleistocene Ice Age, the reason for extinction is unknown.Eight, MammothLength up to 5 meters, shoulder height 4.5-5.2 meters, weight 10-22 tons. The Mammoth lived from 4800000 years to 4000 years ago in the Middle-Late Miocene, it was a giant in the Ice Age, once one of the largest elephants on earth, and one of the largest mammals that lived on earth. The last group of Siberian mammoths went extinct about 2000 years ago, which coincided with the time when the pyramids were built in Egypt. The reasons for extinction are four: environmental changes, human hunting, inbreeding, and dog-assisted hunting. However, these are all speculations, and the real reasons are yet to be explored.Nine, Earth SlothStanding height over 6 meters, weight up to 4 tons. The Earth Sloth lived in South America in the Late Pleistocene and Middle Pleistocene (about 10000 to 100000 years ago), it was the largest mammal on land at that time, with its strong arms and huge claws it could even pull down entire trees, it had no enemies, and the hunting tiger with sharp teeth also had to give way to it. In the Late Pleistocene, the Earth Sloth and other primitive mammals were affected, causing a crisis of extinction, many primitive mammals such as the toothy beast, the toothy tiger, the cave elephant and the sword-tongued elephant went extinct, at the same time the Earth Sloth went extinct. It is estimated that the arrival of humans may have dealt a huge blow to the large animals in South America.Ten, Prehistoric RhinocerosLength 7-9 meters, shoulder height 4.8-5.5 meters, weight up to 22 tons. The Prehistoric Rhinoceros mainly lived in the Middle-New Stone Age, the rhino family included 9 genera, the most largest land mammal is the Gansu rhino genus. The rhino family went extinct in the Early-Middle Miocene, the reason for extinction is unknown.

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