Have you ever thought about why pet dogs can have various appearances, while pet cats are usually surprisingly consistent in appearance, only the color of fur will be different; have you ever thought about why we call lions and tigers "big cats", and if we call wolves "big dogs" or foxes "little wolfs", it will look awkward. The essence of these two problems is actually the same, that is, all felines look surprisingly consistent, basically only in size and fur color, while canines have various body forms and various lifestyles.
In fact, in the animal world, most groups are like the Canidae family, with species diverse from each other, and few are as unified as the cat family. For example, there are several species of bear families on Earth now, but almost every species is different. There are highly specialized plant-eating animals - pandas and glasses bears (like to eat fruits and bromeliads); there are polar bears that step into the ranks of marine mammals; there are also lazy bears that eat societies. They are genetically similar, but their lifestyle and appearance are completely different.
There is only one way of life in the cat family - hunting machines, and basically only one appearance - round face! So, the question is, why is this the case for cats? Why haven’t they become as diverse as other groups? How similar are
cats? The similarity between felines is indeed much more similar than we think. You may not believe that even the most professional expert will find it difficult to distinguish the skulls of lions and tigers without any assistance.
Moreover, not only today's felines, but also extinct in ancient times, although they are of various species, they are surprisingly consistent in their lifestyles and physiological structures, except for their size. We mentioned earlier that pet cats are not as diverse as pet dogs, and this reason is that they are surprisingly consistent with their cat family.
The heads of all cats are the same, big and round, and will not be lengthened as they mature (in fact, this is the case for us humans). Pet dogs are different. They also have round faces in infancy, but as they grow, their heads are lengthened, and it is precisely this developmental variation that breeds with different face shapes.
Since pet cats only get bigger as they age, there is nothing to cultivate in terms of appearance and it is difficult to become diverse. The reason why cats' heads are like this is because their bodies are very professional and for the head, they are mainly reflected in the teeth. Each mammal, known as a carnivore, including cats and dogs, has a fourth premolar of the upper jaw and a first molar of the lower jaw, which forms a pair of molars suitable for cutting meat.