Crocodiles are terrifying animals to look at, who seem at home among dinosaurs and other prehistoric creatures. They live near rivers, swamps and small lakes, and they are globally known for putting on a spectacular show on the Mara River, where they ambush wildebeests migrating across the East African savannah every year. Apart from their unusual appearance and hunting prowess, here are some interesting facts about crocodiles you probably did not know.
1. The largest reptiles
Crocodiles currently hold the world record for the largest living reptile. They are not just overgrown lizards! Freshwater crocodiles can weigh up to 500 kilos and measure 5 meters in length. Some saltwater crocodiles can reach a mass of 1,000 kilos and measure up to 7 meters nose to tail. Crocodiles have an average lifespan of 70 years because they have very few predators.
2. They are closely related to dinosaurs and birds
Crocodiles are the closest living relative to dinosaurs and birds. Birds are actually dinosaurs that evolved by growing wings and feathers, known as avian dinosaurs! The earliest crocodiles first appeared about 240 million years ago, around the same time that dinosaurs started roaming the earth. Scientists have worked out that these incredible reptiles shared a common ancestry.
3. Have huge strong jaws
The most impressive crocodilian feature is, without a doubt, their massive jaws. Their jaws have two rows each of long, sharp teeth, with 64 teeth in total. When a crocodile loses a tooth, a new one starts to grow almost immediately! Crocodiles have the most powerful bite in the animal kingdom and are thousands of times more powerful than a human’s bite. This is due to the extremely strong muscles that hold the jaws together. These muscles can also keep the jaws open for hours, even when underwater as the crocodile waits for their prey.
4. They do not chew
Despite their razor-sharp teeth and strong jaws, crocodiles don’t actually chew their food. Their tongue doesn’t even move; it is stuck to the floor of their mouth. They simply rip out chunks of flesh (bone, hide and all) from large prey and just swallow them whole. They do this by biting down and then twisting their entire body violently to tear off the flesh. Sometimes when food is plentiful, crocodiles store away their catch and let it rot a little bit so that it’s easier to bite and swallow. Gross, but it’s not a problem when you can barely taste your food.
5. They swallow stones
Many crocodiles have been known to swallow stones, which at first seemed like a strange habit. It turns out these stones help them sink more easily into the water which keeps them rooted to the bottom so they can lay in wait for prey. Crocodiles are stealthy hunters, and staying hidden under the murky waters prepares them for a surprise attack when their prey shows up. The stones also help with their digestion, sort of in the same way that chickens swallow sand grains to improve their own digestion.
6. They lay eggs in the sand
Crocodiles are suited for a life in water and on land. However, due to their hunting habits, they spend most of their time in the water. Like other reptiles, they reproduce by laying eggs, but they never lay their eggs in water. The female crocodile goes out to land, digs a shallow nest in the ground, lays her eggs and covers them with sand. Burying the eggs inland protects them from predators, plus, the sand has all the right conditions necessary for incubation. Their eggs are about the size as a chicken’s egg but take four times as long to hatch.
Eighty days later, the baby crocs are ready to burst out of their shells and dig themselves out of the sand. The mother crocodile goes out again to the nest, this time to help the new hatchlings dig their way out and escort them to the water. She carries them with the same powerful jaw, but very delicately!
Do you know how a hatchling ends up being either male or female? Well, if a crocodile’s egg is incubated at very low or very high temperature, the resulting hatchling becomes male, and at a medium temperature, it becomes a female. This is called temperature-dependent sex determination, and it’s quite common other reptilian species.
7. They make tears but don’t cry
There is a common myth that suggests crocodiles cry as they feed. The truth is, as the crocodile eats, it swallows a lot of air that comes into contact with its tear glands; this forces an involuntary excretion of tears that can be seen around the eyes. Stories of ‘crocodile tears’ and why they cry are told in many folklores from different communities all over the world.