Studies have uncovered ancient spiders from hundreds of millions of years ago

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Spiders are a common animal, but due to the scarcity of early fossils, little is known about their origin and evolutionary history. The spider fossils found this time are preserved in four pieces of Burmese amber from 100 million years ago, and although the length is only about 3 millimeters, it is extremely complete. The slender tail whiskers found in spiders surprised the researchers. In our impression, spiders have large and small ones, but they have no tails, but spiders 100 million years ago have long tails, and look down at the ancient spider news of 100 million years ago to understand the details.

A team led by Wang Bo and Huang Diying, researchers at the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, respectively studied the "monster spider" in Myanmar amber 100 million years ago, the Ying's Chimera spider, and found the above situation.

On February 6, two research papers were published online in a "back-to-back" manner in the international academic journal Nature Ecology & Evolution.

Regarding the origin of the name "Chimerarachne yingi", Wang Bo explained that chimera is derived from the monster Chimera in ancient Greek mythology, reflecting the mixed characteristics of the multi-class arachnid biological characteristics of the new species; Arachne means spider. The species name yingi comes from the surname of ms. Ying Yanling, the provider of the amber fossil specimen, who provided four fossils containing four spiders.

Cobwebs are distributed in almost every corner of the world.

47273 species in 4075 genera! This latest statistics, the World Spider Catalogue (2018), an online database affiliated with the Natural History Museum in Bern, Switzerland, was updated on 5 February 2018.

The world's spiders, which together weigh as much as the 478 Titanic ships, eat about 400 million to 800 million tons of prey each year, more than the world's population.

In the 100 million-year-old "advanced" Burmese amber fossil provided by Ms. Ying Yanling, two of the spiders are males, with tiny individuals, less than 2 mm in length (not counting tail whiskers), and the body is divided into cephalothorax and abdomen, with 6 eyes directly in front of the cephalothorax.

Huang Diying said that the most special feature of the "Ying's Chimera Spider" is that it has a slender tail whisker, which is more than 1.5 times longer than the body. The tail whiskers are divided into more than 70 sections, each with a slender ring of bristles.

Regarding the role of the tail of the "Ying's Chimera Spider", Wang Bo speculated that its tail is straight, cannot swing at will, and has no venom glands, so it may be a perceptual organ for detecting the environment and odors at the back of the body. A lot of hairs on the tail, probably sensory hairs.

In addition to the tail whiskers, the front and rear spindles of the "Chimera Spider" are well developed, and the outer spinner has a silk gland on the inside of each section; Its foot has the distinctive characteristics of a spider: it has large bristles and fine hairs on the foot, and the end of the foot is a toothed lateral claw, middle claw, and prominent inter-claw protrusion.

Huang Diying's team believes that the discovery of the "Ying's Chimera Spider" makes up for an important missing ring in spider evolution, that is, the lack of ring between ural spiders and modern spiders. Because the "Chimera Spider" has both the former's unique slender tail whiskers, and the latter's multi-knotted spinning device and silk gland structure.

Huang Diying's team said that the fragment fossil "Attercopus" found in the Devonian (about 359-419 million years ago) strata in New York, the United States, allowed researchers to reconstruct an extinct arachnid: ural arachnids. They have long tail whiskers and claw-like structures endemic to spiders.

But in modern spiders, the long tail whiskers are gone. Only in a small number of spiders, a short protrusion remains, called the gluteal plate.

Huang Diying's team believes that the ancestors of the "Ying's Chimera Spider" can be traced back to the Ural spider order. Through the study of the Chimera Spider, the team believes that the spinner and specialized whiskers are not very "evolutionary" features. Spiders are more primitive than whips (whip scorpions), whipworms (whip spiders), cracked shields, and so on.