Crocodiles are one of the robust animals who survived the biggest asteroid strike in the Cretaceous period.
They are semi-aquatic reptiles that live in tropical regions of Asia, Africa, Australia, and America. The reptiles have an efficient body shape and versatility to survive in extreme conditions. According to recent research, these species can withstand enormous climatic changes.
The physical trait of crocodiles allows them to become successful predators. The streamlined body of the species helps them to swim. And the external structure of crocodiles is an indication of their predatory and aquatic lifestyle. Crocodiles can live in or outside the water. They can even survive in darkness. They have a tough physical design; hence they can face any climatic extremities and severe injuries.
Crocodiles generally prefer warm climatic conditions. The species are cold-blooded; hence they can not regulate their body temperatures. They take warmth from the surrounding.
Over 66 million years ago, space rocks smashed all the natural habitats, including animals and plants in the Gulf of Mexico. During that calamity, almost all living beings died, and a large species wiped out from Earth. But, crocodiles survived the tragedy by drawing the energy from the sun.
The incident speaks out loud that unlike warm-blooded animals (mammals or birds), crocodiles do not need to eat much to survive, and they do not need to change or evolve.
Over the years, the crocodile species have undergone very little change. Researchers believe that the lack of evolution and their limited diversity might help them survive the major mass extinction.
The crocodiles of today have many similarities with the crocodiles of the Jurassic period. This indicates that crocodiles have undergone slight or almost no change from some 200 million years ago. Researchers at the University of Bristol say that the species’ efficiency to withstand the severe global tragedy might be the reason for the minimum change in crocodiles or the slow rate of evolution.
Author Dr. Max Stockdale said that the crocodiles’ well-designed body might be the reason for their survival at the end of the Cretaceous period. He added that the species had a versatile lifestyle, which helped them to adapt to the extreme climatic changes.
Crocodiles can hold their breath for around one hour underwater and own an incredible ability to hold oxygen. There are only 25 species of crocodiles that are alive today. They are great swimmers and also able to move on the land with surprising speed- especially when they are angry or alarmed.
According to Dr. Stockdale and his colleagues, crocodiles have a “start-stop” phenomenon towards an evolution which majorly depends on the climate and surrounding. This pattern is known as “punctuated equilibrium” described in Nature Communications Biology. The theory proposes that some species stabilize their evolutionary rate and show very little or no changes. This state is also known as “stasis.” The phenomenon also explains why some prehistoric species are no longer alive. Many extinct species underwent “punctuated equilibrium,” including gigantic animals like dinosaurs, fast runners, diggers, plant-eaters, and water serpent-like monsters.
Dr. Stockdale, a geographical scientist, shared that his team has analyzed the species’ rate of evolution using machine learning. The evolutionary rate can be defined as the change that occurs within a species over a considerable amount of time. The researchers can find the rate of evolution by comparing different measurements from the fossils.
For the research, the scientists collect a few required data of the animal, including the species’ growth, how much food they need to survive, how fast do they grow, how big are their populations, and how they are likely to extinct.
According to the study, the researchers find out that Crocodiles can eat anything in their surroundings. They have a strong immune system. Just like bats, crocodiles can resist disease. The reptiles can survive without any large meals for a long time. Their babies mature much quickly. Crocodiles can also undergo hibernation and survive with the huge temperature drops; therefore, they survived the ice ages.
The crocodile species also flourish more in warm conditions because they need external heat to keep themselves warm. The climatic condition of the Cretaceous period was much higher than the temperature of today; hence there were more species of crocodiles in that era. Now a group of researchers has planned to study them more to find out why some prehistoric species became extinct while others survived.
Crocodiles are amazing creatures, and they have lived through two mass extinctions. The unique design of the species helps them to stand up to the ultimate living condition. Their body is able to sustain severe injuries.