Crocodiles: 200 Million-Year-Old Freshwater Dominators, Outcompeting Mammals
Reptiles once ruled the Earth for 2.3 billion years, with the dinosaurs dominating the land during the Jurassic and Cretaceous periods, crocodiles dominating rivers and lakes, and pterosaurs soaring in the sky. Fish dragons, long-necked dragons, and successively held sway over the seas.The entire Earth, land, sea, and sky, was ruled by one branch of animals. This was the first and only time in Earth's geological history, and remains so to this day.
Crocodiles were the dominant freshwater creatures during the dinosaur era.
Approximately 66 million years ago, at the end of the White, a giant meteor fell to Earth, marking the end of the age of reptiles. Dinosaurs, pterosaurs, and all went extinct in this disaster, and mammals quickly rose to become the new dominant species. However,Crocodiles did not go extinct with them, they survived, and continued to hold sway in freshwater, becoming the 'last emperors' of reptiles, and freshwater became the last 'reserve' for reptiles.As evolutionary pioneers, mammals' strength is undeniable. But how did freshwater remain under the control of crocodiles, despite mammals' dominance on land?
Water's thermal capacity is three times that of air, meaning that water absorbs or releases three times as much heat as air for every degree it rises or falls. This allows creatures adapted to water to maintain a stable body temperature, avoiding extreme temperatures.
This also means that water conducts heat more efficiently than air, meaning that warm-blooded animals lose heat quickly in water. Warm-blooded animals lose energy in water, which is a disadvantage.In freshwater, there were a lot of brown food chains, which relied on dead organic matter. This was the basis for the ecosystem. In terrestrial and shallow marine ecosystems, brown food chains were dominant.At the end of the White, the disaster caused the collapse of the green food chain, and for a long time, a lot of dead organic matter was washed into the river. The brown food chain maintained it, supporting some small fish and crabs. Crocodiles relied on these to usher in the new era.
Crocodile times: Crocodile, up to 10 meters long, weighing over a ton.
After the extinction of the dinosaurs, mammals took 20 million years to surpass the dinosaurs and also to defeat the birds that were trying to seize the ecological niches. They became the masters of the Earth, but crocodiles remained in freshwater for 66 million years.Physiological tolerance is key. Freshwater ecosystems are difficult to support large animals because of low productivity, instability, and isolation. The crocodile has achieved the extreme adaptation to freshwater.The crocodile's metabolic rate is low, they only need a small amount of food to survive for a long time, which is something that large mammals cannot do.The crocodile can also survive without eating and drinking for several months in the mud.The crocodile is also a powerful predator. The crocodile is a powerful predator, which is more worthy of human respect than lions and tigers.However, due to indiscriminate hunting and habitat destruction, crocodile skin trading, and other factors, the last freshwater emperor is now in danger. The American crocodile, the Cuban crocodile, the Siamese crocodile, the gharial, and the American crocodile are all critically endangered.
Large cat species became the king of beasts for only 3 million years, while the crocodile has been the master of freshwater for at least 66 million years. From this point of view,The crocodile is more worthy of human respect than lions and tigers.However, due to indiscriminate hunting and habitat destruction, crocodile skin trading, and other factors, the last freshwater emperor is now in danger. The American crocodile, the Cuban crocodile, the Siamese crocodile, the gharial, and the American crocodile are all critically endangered.
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