18/10/2022
Interesting facts about mammals
Fact 1. Once upon a time there were more different mammals on Earth than now. In the modern world, there are about 5,500 species, but earlier there were about four times as many. Alas, evolution is merciless, and many of them died out long before humanity began to exert its influence on the appearance of the planet. Some simply failed to adapt to the changed conditions, while others became victims of competition.
Fact 2. There is only one cold-blooded mammal on our planet. This is a naked digger, a mouse-sized rodent living underground, and these creatures are unique in many ways. They live 20 times longer than mice (up to 30 years), do not feel pain, are not afraid of high concentrations of carbon dioxide and, with rare exceptions, never have cancer.
Fact 3. Oddly enough, mammals descend from reptiles. What exactly factors led to the fact that evolutionary processes have changed them so much is unknown. But warm-blooded animals are so different from their scaly ancestors that scientists have learned about their origin from reptiles relatively recently.
Fact 4. Man is also a mammal. Moreover, primitive people were covered with wool quite thickly, we are not at all hairy compared to them. However, everything is relative - humans have the same amount of hair per square centimeter of skin as chimpanzees, it's just that our hair is much shorter and thinner, so they generally seem almost invisible.
Fact 5. The most ancient mammals appeared on Earth, according to scientists, about 230,000,000 years ago. For millions of years, they were all very small, and therefore extremely vulnerable to the reptiles that ruled the world. The situation began to gradually change 165,000,000 years ago, when the age of dinosaurs began to end. The last ancient lizards died out 66,000,000 years ago, and since then mammals have occupied a dominant position in the world.
Fact 6. All mammals have some similar features without exception. In the inner ear, hidden in the skull, they have three very small bones connected to the eardrum. In general, all representatives of the class have them, from a person to the aforementioned naked digger.
Fact 7. Marsupial mammals appeared on Earth much earlier than placental ones. They were found on all continents, but died out a long time ago everywhere except Australia, which was the first to break away from the supercontinent Pangea. Therefore, some relic life forms have been preserved there.
Fact 8. Platypuses caused most questions among scientists at one time. These animals, which Europeans met after the discovery of Australia, for a long time could not find a place in the classification. They feed their young with milk, but lay eggs and do not produce live offspring, and a number of signs indicate their relationship with birds. Ultimately, they were still classified as mammals.
Fact 9. All mammals really feed their offspring with milk, which is why they got such a name. But some of them simply don't have ni***es! The aforementioned platypuses, for example. Their milk is secreted from the mammary glands and flows directly through the wool, and the cubs lick it off.
Fact 10. Despite the dominance of dinosaurs that lasted for many millions of years, mammals are still the largest living creatures that have ever existed on Earth. These are blue whales, which, in size and mass, surpass in general any form of life that has ever roamed the land or splashed in the oceans.