Cloven hoofed animals are called cloven hoofed because they have an even number of toes. In other words, each foot of the cloven hoof has either two toes, equivalent to the third and fourth toes of a person, or four toes, equivalent to the second to fifth toes of a person, but the center of gravity is between the third and fourth toes.
The talus on the cloven hoofed ankle is another of the most characteristic parts. This bone has two pulleys (i.e. articular surface). The upward pulley is connected with the tibia and the downward pulley is connected with the other tarsal bones of the ankle. The talus of cloven hoofed is completely different from that of odd hoofed with only one pulley. The talus of this double pulley enables its hind limbs to bend and extend to a great extent. With the help of this feature of talus, most cloven hoofed animals have extraordinary jumping ability.
The important reason why cloven hooves have evolved more successfully than odd hooves is that most cloven hoofed animals have a special digestive system, which is a stomach and related intestinal system composed of four gastric chambers. Cloven hoofed animals with this digestive system are called ruminants. In the feeding process of ruminants, plant food first enters the first gastric chamber rumen and the second gastric chamber honeycomb stomach after being bitten and cut off. The food in the stomach is digested into soft lumps under the action of bacteria, and then these soft lumps are re driven back to the mouth for chewing. This process is rumination. After the re imported food pieces are chewed into small food pieces, they are swallowed into the third and fourth stomachs, namely the double Omasum and abomasum, and further digested.
This complex digestion process is the reason why cloven hoofed animals gain advantages in the struggle for survival. They can quickly swallow a large amount of food in a short time before the arrival of a strong enemy, and then quickly escape the danger to a safe place. At this time, they can ruminate the food for careful chewing and thorough digestion. This feature of swallowing a large amount of food quickly and then ruminating and digesting makes cloven hoofed animals still get enough food and digest fully in the process of escaping the pursuit of large carnivores.
This characteristic of cloven hoofed animals has obvious competitive advantage in the late Cenozoic when the range of open grassland is expanding. Because on the grassland, although both cloven hoofed and odd hoofed have achieved rapid running ability, fierce predators can also be pursued quickly. However, cloven hoofed can eat quickly before escaping, which lays a foundation for their absolute victory in the survival competition with odd hoofed animals.
According to the fossil records, even hoofed and odd hoofed appeared on the earth almost at the same time. In the early evolution stage, odd hoofed was still significantly dominant. However, with the passage of time, the species and individual number of odd hoofed gradually gave way to even hoofed, which made the latter dominant in the Late Cenozoic.