It can be a fish as big as a house, it is scary to see it;
It can also be a spider as big as a washbasin. The actual size is not too big, but it is scary enough
When it comes to arthropods, most people think of bugs that are a few centimeters long. However, there is a “giant insect era” in history, the Carboniferous. At that time, arthropods were huge in size. At that time, giant insects dominated the land, and other animals could only avoid them. The Carboniferous, which lasted from 359 million to 299 million years ago, lasted for about 60 million years. At that time, the earth’s climate was warm and humid, with large tropical rainforests and swamps growing, and the atmospheric oxygen content reached 35%, which is 21% higher than today’s. The oxygen content is much higher. It is very suitable for arthropods to multiply and thrive, thus bred a large number of giant insects.
Arthropods began to migrate from the ocean to the land about 450 million years ago. Most of them have a hard shell to prevent water loss, strong legs enable them to support their own weight, easy to walk. By the Carboniferous, insects, arachnids, and polypods among the arthropods all completed their landing trips, and many large-scale populations developed. Among them, the famous giant centipede, they have been very prosperous in the early Carboniferous, and they are widely distributed in today’s Europe, North America and Australia. The segmental thorax belongs to the Pylopod class of the polypedal subdivision, while the centipede belongs to the class Labipod. They are not in the same class and are closely related. Therefore, the segmental thorax is not a giant centipede, but it is a large class with Malu. There are many species of this genus, the small ones are only a few centimeters, and the large ones can reach two meters. The fossils of the giant nodule breast footprint found in New Mexico resemble two parallel tire tracks. These marks show that the nodule breast is at least half a meter wide and 2.4 meters long. It is the largest terrestrial arthropod in history, and it is in any era. A kind of millipede monster.
Insect landings can be traced back to the early Devonian about 400 million years ago, and the earliest wingless insects such as silverfish. The only winged insects that have appeared in the Carboniferous are dragonflies, mayflies and cockroaches. The dragonflies at that time were much larger than they are today. The largest one was called the giant veined dragonfly with a wingspan of 74 cm. It was a predator that fed on small animals. At that time, it was the overlord of the sky and played a similar role to today. The role of the eagle. The scorpions and spiders of the arachnids also landed in the Devonian. At the same time, their distant relatives-the sea scorpion (that is, the scorpion horseshoe crab, extinct), and the largest sea scorpion-the Rheinyecker horseshoe crab, were rampant in the sea. A huge arthropod with a total length of 2.5 meters.
The real scorpions that lived on land during the Carboniferous period were also huge. The Pumono scorpion appeared 350 to 330 million years ago. It is also called the lung scorpion, so it is also known as the “breathing scorpion.” Its appearance is similar to the current scorpion, but its body length is nearly 1 meter (about 70 cm). The lung scorpion is a terrible killer. It mainly captures other arthropods as food, and its tail spines are enough to bring down some small quadrupeds. The huge body of the Carboniferous arthropods is unprecedented. Why did they evolve like this? The current mainstream explanation is related to the atmospheric environment at that time. We know that arthropods are different from vertebrates. They do not have lung organs in the usual sense for gas exchange. Among arthropods, aquatic species mainly rely on the gills respiratory system, and terrestrial species mainly rely on the airway in the exoskeleton to breathe. This method of breathing by oxygen diffusion and penetration made arthropods at that time in an oxygen-rich state for a long time, which greatly stimulated body growth. There is also a view that during the Carboniferous period, the terrestrial ecosystem was relatively simple, and the structure of the food chain was relatively simple. Predators and prey could only adapt to the living environment through the evolution of body size. Through natural selection, the body size became larger and larger. .