Tiktaalik moving on to land was a huge breakthrough in evolutionary history. It would allow for other species to prosper on the continents of planet earth, and eventually would allow for the human race to come into existence.
Throughout the Devonian, amphibians walked the Earth. Ever since Tiktaalik had come on to land, it had evolved small legs, enabling it to walk on land. These legs were also webbed, and it had a fin-like tail, allowing it to swim in the water. This meant it could both swim in water and walk on land, which made it the first amphibian. The amphibians of the time were also quite large, and the once mighty arthropods had shrunk dramatically. Life on land was finally taking shape, and some familiar creatures could be seen at this time. Creatures such as sharks, many kinds of fish, and amphibians could be seen roaming the earth, and many types of vegetation and trees were beginning to evolve. Earth was starting to look like home.
After many years, Earth was beginning to look more recognizable. Tall green forests of trees covered the Carboniferous landscape, the ground was dominated by seed ferns, sharks roamed as top predators, and amphibians could commonly be seen resting among the river banks, and had evolved adaptions to life on land.
Even insects could be seen all around the forests, and would soon take to the skies. Even arthropods were making a comeback. Though these were not regular insects or arthropods. These creatures were giants. Huge dragonflies such as Meganeura had wingspans the size of an eagles'. Armored centipedes the size of crocodiles crawled on the forest floor, towering above the largest amphibians as they reared upwards.
These insects and arthropods were so large because the oxygen level at the time was apparently very high. The amount of oxygen that flows through the insects' or arthropods' body takes a toll on it's size, and the insects and arthropods of the time were obviously affected by this. Though the creepy-crawlies were not the only ones who were changing.
As a result of becoming adapted to conditions on land, amphibians evolved different types of eggs that would cope with the ground environment. These eggs evolved hard shells, protecting the babies of the new species inside of them. These types of eggs were made to be laid on land rather than in water. After many years of evolution, these creatures would be known as reptiles. Reptiles did not have the adaptions to water that amphibians had yet, but in many ways they had may more advantages. Reptiles had evolved a protective set of scales on their skin, unlike the slimy, vulnerable texture of an amphibian. The reptiles of time had also evolved an advanced heart system, which would pump blood at a much faster rate, giving the reptiles much more energy, unlike the amphibians, who were often somewhat sluggish on land. And, these reptiles had evolved a somewhat long set of legs, which would help for running away from predators, such as the giant spiders of the time. The fact that reptiles were so small meant they were in constant danger of being hunted, which meant they needed the necessary adaptations for outrunning their killers.
The Carboniferous seemed like the heyday of life on Earth, with vast, flourishing forests and many new species of animals. However, it couldn't last forever. Before the end of the Carboniferous period, an extinction event occurred, an event that would decimate biodiversity. The climate was drastically changing on earth, with ocean levels rising and many glaciations. Oxygen levels also drastically dropped, and so the insects and arthropods of the time barely survived into the Permian. The temperature and environment changed from hot and humid rainforest to cool and arid desert. Many amphibians were not adapted to these drastic changes, and so many died out. One of the only groups of animals that survived into the Permian were the reptiles. They grew dramatically in size, and some evolved sharp sets of teeth. Others grew sails on their backs, to help keep cool in the arid deserts. It was because of this that the reptiles would, for millions of years, dominate the Permian era, and even give birth to our closest ancestors. Our own species.
Even insects could be seen all around the forests, and would soon take to the skies. Even arthropods were making a comeback. Though these were not regular insects or arthropods. These creatures were giants. Huge dragonflies such as Meganeura had wingspans the size of an eagles'. Armored centipedes the size of crocodiles crawled on the forest floor, towering above the largest amphibians as they reared upwards.
These insects and arthropods were so large because the oxygen level at the time was apparently very high. The amount of oxygen that flows through the insects' or arthropods' body takes a toll on it's size, and the insects and arthropods of the time were obviously affected by this. Though the creepy-crawlies were not the only ones who were changing.
As a result of becoming adapted to conditions on land, amphibians evolved different types of eggs that would cope with the ground environment. These eggs evolved hard shells, protecting the babies of the new species inside of them. These types of eggs were made to be laid on land rather than in water. After many years of evolution, these creatures would be known as reptiles. Reptiles did not have the adaptions to water that amphibians had yet, but in many ways they had may more advantages. Reptiles had evolved a protective set of scales on their skin, unlike the slimy, vulnerable texture of an amphibian. The reptiles of time had also evolved an advanced heart system, which would pump blood at a much faster rate, giving the reptiles much more energy, unlike the amphibians, who were often somewhat sluggish on land. And, these reptiles had evolved a somewhat long set of legs, which would help for running away from predators, such as the giant spiders of the time. The fact that reptiles were so small meant they were in constant danger of being hunted, which meant they needed the necessary adaptations for outrunning their killers.
The Carboniferous seemed like the heyday of life on Earth, with vast, flourishing forests and many new species of animals. However, it couldn't last forever. Before the end of the Carboniferous period, an extinction event occurred, an event that would decimate biodiversity. The climate was drastically changing on earth, with ocean levels rising and many glaciations. Oxygen levels also drastically dropped, and so the insects and arthropods of the time barely survived into the Permian. The temperature and environment changed from hot and humid rainforest to cool and arid desert. Many amphibians were not adapted to these drastic changes, and so many died out. One of the only groups of animals that survived into the Permian were the reptiles. They grew dramatically in size, and some evolved sharp sets of teeth. Others grew sails on their backs, to help keep cool in the arid deserts. It was because of this that the reptiles would, for millions of years, dominate the Permian era, and even give birth to our closest ancestors. Our own species.
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