Spiders are arachnids, characterization, description and a photo
Arachnids – detachment of arthropods helitserovyh subtype. The name “arachnids” came from the female name Arachne. She was a weaver, which angered the gods turned into a spider. This weaving of a web – the main feature of many species of spiders. Recently, the remnants of the ancient spider webs were found. With the help of a special analysis experts have calculated the age of networks. They are now about two hundred and forty million years. Also remains of ancient spiders were found. Their age is more than three hundred sixteen million years. Surprisingly, the valuable specimens are still preserved.
It is known that the first spiders have eight legs. They were mainly terrestrial life. Their networks are far from ideal. First Web spiders significantly different from their descendants networks. Threads randomly intertwined, were sticky crude. Insects clumsily pulled spider strings between the stones, plants, eating “weave cloth.” But it later. First cobweb spiders used as a protective shell for the female egg. In addition, arthropods can not perfectly control his own body. Sticky thread periodically protrude from the abdomen. We can say that this type of networks, the insects are not used. Production of food is, provided no difficulty.
The most outstanding hallmark of modern spiders with their ancestors was the presence of long, thick tail. The first were tiny spiders. Body length was five millimeters, tail – two.
Unfortunately, it is not known what was needed tail. Some scholars suggest that the body produces another sample gossamer thread.