Crocodiles are reptiles of the order Crocodylia, which includes the alligators, gharials, and true crocodiles (family Crocodylidae). The ancestors of all these animals are known as crurotarsos and appeared about 240 million years ago. These majestic reptiles colonized the entire world and grew to staggering sizes.
Currently, there are only about 23 species that are distributed throughout the warmest regions of the planet. Throughout history, they have been considered devourers of unworthy souls, symbols of power and gods of fertility. But who really are these reptiles? We tell you about it in this article about the types of crocodiles, their characteristics, names and examples.
Crocodile Characteristics
All types of crocodiles are carnivorous and voracious predators They have a semi-aquatic way of life and can spend a lot of time out of the water, where they walk freely. Normally, they can be seen together in a group while sunbathing. This is because they are ectothermic animals and need the heat of the sun to raise their body temperature.
Among its anatomical characteristics, the presence of a very hard skin formed by scales and green, brown or black stands out. This allows them to perfectly camouflage themselves as they lie still on the surface of the water, waiting for prey to approach. To stay submerged for so long, they have their eyes and nose on top of their heads In this way, they can breathe and observe any movement that occurs below. your surroundings.
As for their behavior, they are quite social animals, although they are also dominant. In fact, they are one of the few reptiles that make vocalizations. In addition, the reproductive behavior of the females is very remarkable, as they take care of their eggs and, later, their offspring very efficiently.
Where do crocodiles live?
The ancestors of the crocodiles spread throughout the Earth. However, at present, their distribution is limited to some areas of America, Africa, Asia and Oceania In these places it is only possible to find them on the equator and the tropics, where the heat allows their reproduction.
The habitats of the crocodile are the large rivers, swamps and lakesDue to human occupation and the climate change scenario, these ecosystems are very vulnerable and are disappearing. This is one of its main threats and has contributed to many species of crocodiles being considered in danger of extinction.
If you want to know more about the crocodile's habitat, we recommend this other article on Where crocodiles live.
How many types of crocodiles are there?
The order Crocodylia is made up of several families or types of crocodilians. They are as follows:
- Gavial crocodiles (Gavialidae)
- Caimans or alligators (Alligatoridae)
- True Crocodiles (Crocodylidae)
In the following sections we will see who is part of each group and what their main characteristics are.
Gavial crocodiles
Gavial crocodiles are crocodilian reptiles that make up the Gavialidae family, although there is much controversy about their taxonomy. These animals are characterized by their bulging eyes and their snout, which is thinner and longer than that of the other crocodiles. It is a very useful snout for hunting fish, which are the basis of their diet.
Most of the gharials that have existed disappeared during the Triassic-Jurassic extinction. Today only two known species remain:
- False gharial (Tomistoma schlegelii): inhabits the humid areas of Indonesia and Malaysia.
- Gharial crocodile (Gavialis gangeticus): lives in the swampy areas of the Ganges River in India.
Caimans or alligators
Caimans or alligators are crocodile-shaped reptiles that form the Alligatoridae family. They differ from other types of crocodiles by their wide and short snout In addition, unlike the Crocodylidae family, these animals lack s alt-excreting glands, so which live exclusively in fresh water.
Within the alligator family, we can find 8 species of crocodiles or alligators that are grouped into 4 genera:
- True alligators or alligators (Caiman): there are 3 species (C. crocodilus, C. yacare and C. latirostris), all inhabitants of the Neotropics.
- Orinoco black caiman (Melanosuchus niger): lives in the Amazon and Orinoco river basins in South America.
- Dwarf caiman (Paleosuchus): this genus includes the dwarf caiman (P. palpebrosis) and the postrusso caiman (P. trigonatus). Both are inhabitants of the Amazon.
- Aligátores (Alligator): there are only 2 species. One of them is distributed in China and is known as the Chinese alligator (A. sinensis). The other is the American alligator (A. mississippiensis), found only in the rivers and swamps of the southeastern United States.
Discover more Animals of the Amazon in this other article.
Real crocodiles
The Crocodylidae family is the most diverse of all types of crocodilians. According to the most recent studies, these animals arose in Australasia at the beginning of the Eocene, only 56 million years ago. Later, they colonized America and Africa, in whose fresh and brackish waters they are now relatively abundant.
True crocodiles include some of the larger species The Nile crocodile (Crocodylus niloticus), for example, can reach reach 6 meters in length. In addition, these animals are very long-lived and usually live between 50 and 80 years. They are reptiles with strong muscles and a powerful jaw. From this, large teeth come out that remain outside the mouth when it is closed.
Another distinctive feature is its snout, which tapers from base to tip and is longer than that of alligators. On the eyes and on the tongue they have glands that excrete s alt For this reason, they can be found in slightly s alty waters, such as marshes or river deltas. This ability would have allowed their ancestors to cross the Pacific and Atlantic oceans on tree trunks left adrift after a storm.
Currently, there are only 13 or 14 species of true crocodiles that are grouped into 3 genera. They are as follows:
- Crocodiles (Crocodylus): is the most diverse genus of all types of crocodiles and includes 11 species that are distributed throughout Africa, America, Asia and Oceania. The best known are the American crocodile (C. acutus) and the Nile crocodile (C. niloticus), which is the only African crocodile.
- Dwarf crocodile (Osteolaemus tetraspis): Today there is debate as to whether there are two species or just one. In any case, both populations live in Africa.
- Slender-snouted crocodile (Mecistop s cataphractus): This species of crocodile lives in southwestern Africa and is critically endangered of extinction. Meet the most endangered Animals in the world in this article.
S altwater Crocodiles
As we said in the previous section, true crocodiles (Crocodylidae) have glands above their eyes and on their tongues that allow them to “cry” the s alt that enters in your body This is where the expression “crocodile tears” comes from, although they are not tears, but a very effective method of controlling the s alt concentration in your body. This feature has allowed some types of crocodiles to enter the sea.
Sea Crocodile
Within the Crocodylidae family there is a species known as the marine crocodile. It is Crocodylus porosus, a reptile that lives in South Asia, Indonesia, the Philippines and Malaysia. This animal inhabits brackish rivers, swamps, lakes and estuaries. However, it has a high ability to tolerate s alt waterFor this reason, on some occasions it has been seen going into the sea to hunt.
The Thalatosuchians
The suborder Thalattosuchia is a group of marine reptiles related to crocodiles. These animals were lizard-shaped reptiles with the head of a crocodile and fish fins. During the Cretaceous, they coexisted with the dinosaurs and inhabited the seas of much of the world until their extinction. For this reason, they are sometimes mistakenly classified as types of marine dinosaurs.
Most of these s altwater “crocodiles” had a long snout similar to that of gharials, so it is believed that they fed on fish. Some of them reached almost 10 meters in length, such as Machimosaurus rex. Due to their morphology, it is thought that they were semi-terrestrial, so they could go out to the beaches to sunbathe or lay their eggs.
