Crocodiles are considered one of the most ancient reptiles, because their first ancestors appeared on earth about 250 million years ago. They are distinguished by a long lifespan, a fairly high speed of movement on the ground, given the size of their torso and legs, and also a kind of digestive system, to improve the work of which they simply need stones.
Instructions
Step 1
Crocodiles are real predators. They mainly feed on aquatic birds and fish, but they often attack various amphibians and do not even hesitate to taste their smaller relatives. In addition, large animals such as giraffes, buffaloes and even lions sometimes get into the crocodile's diet.
Step 2
Despite such a varied menu, the jaws of these reptiles are not designed to chew. The abundance of sharp teeth only allows you to break your prey into smaller pieces, which are then immediately swallowed. At the same time, the crocodile is able to absorb such an amount of food at one time, which will make up a fifth of its weight.
Step 3
The stomach of a crocodile is simply not able to digest such huge pieces of food, consisting not only of meat, but also of bones and even, at times, of hard shells of animals. And the presence of undigested food in the body for a long time can lead to the development of bacteria and even the death of a crocodile.
Step 4
To solve this problem, all crocodiles swallow gastrolith stones, which are fragments of rocks or minerals. Once in the muscular part of the crocodile's stomach, they play the role of millstones, helping to grind fibrous and dense food. In the Nile crocodile, for example, the mass of stones in the stomach can reach up to 5 kg. At the same time, the stones do not cause any harm to the stomach itself, and over time they generally become well polished.
Step 5
In addition to helping with the digestion of food, stomach stones in a crocodile have another important function. They move the center of gravity of these reptiles down and forward, which gives the crocodiles more stability while swimming. Without stones, the crocodile would have to constantly work vigorously with its paws so as not to turn over with its belly up. And this would hardly have allowed so silently approaching the planned production. Gastroliths also perform the same function in dolphins, seals, whales, and walruses.
