The mysterious "long-tailed spider" in Burmese amber 100 million years ago fills the gap in the evolutionary history of spiders
NANJING, Feb. 6 (Xinhua) -- Two international scientific research teams led by Wang Bo and Huang Diying, researchers at the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences, have confirmed the existence of a long tail in the ancient ancestors of spiders by studying the "monster spider" preserved in Myanmar amber 100 million years ago, the Ying's Chimera spider, which has filled in the key link in the origin of spiders.
The results were published on February 6 in the form of two back-to-back papers, NatureEcology & Evolution, a sub-journal of Nature in the United Kingdom.
The picture shows the restoration of the long-tailed "monster spider". Nangu Institute Cartography
Wang Bo told reporters that the ancestors of spiders were once like scorpions, with slender tails and perceptual effects on the outside world. As it multiplies, the spider's tail gradually degenerates. The silk glands and tentacles on the spider's body replace the function of the tail.
"Due to the extreme scarcity of early spider fossils, little is known about the origin and early evolutionary history of spiders. Similar fossils found in the past are not well preserved, especially the structure of the spinner is not clear, and it is impossible to determine whether the specimen belongs to the spider. Therefore, when the long tail of the spider began to exist and how to evolve became a difficult problem in the academic community. Wang Bo said.
The picture shows a Burmese amber specimen. Photo by Yang Yanci
It is understood that the chimera spider specimen found this time comes from the Cretaceous period 100 million years ago, and the length is close to 3 mm. The tail of the spider is very well preserved inside the amber, opening a breakthrough for the study of the origin of ancient spiders.
Wang Bo's research team used high-resolution X-ray tomography systems and other technologies to conduct a detailed analysis of the specimens. The study found that the Chimera spider resembles a spider with a long tail. The fossil presents key features of the spider's basal stem taxa and provides key evidence for understanding the spider's shape, spindles and tentacles.
The scientific research team led by Wang Bo studied the positive mold of the Chimera spider of Ying's (named specimen). Nangu Institute Cartography
Huang Diying's team believes that the fossil can not only be judged by the limb structure as a spider order, but most particularly it has an elongated tail whisker, more than 1.5 times longer than the body, with more than 70 segments, each section has a ring of slender bristles.
Regarding the origin of the "monster spider" discovered this time, Huang Diying believes that its ancestors can be traced back to the fragment fossil "Attercopus" found in the Devonian (about 359-419 million years ago) strata in New York, USA, because they all have the unique claw limb structure and long tail whiskers of spiders.
In this study, two independent research teams have confirmed the basic same conclusions through different aspects of research. However, the specific category of attribution of the fossil has yet to be further studied. (End)
Ecological restoration of the monster spider (Chimerarachne yingi) in Burmese amber. Nangu Institute Cartography
Huang Diying's team believes that the discovery of these "monster spiders" makes up for an important scene in the evolution of spiders, that is, the lack of rings between ural spiders and modern spiders, which have both the unique slender tail whiskers of the Ural spider order and the multi-segmented spinner and silk gland structure almost the same as that of modern arthropod spiders.
Wang Bo believes that the "monster spider" fossil presents the key characteristics of the spider trunk taxon, and has long believed that the key fossils of the origin of spiders should be found in the Carboniferous or older strata, and the emergence of these fossils has challenged and surprised the existing definition of spiders. "Whether the Chimera spider belongs to the order Spider or appears as a separate order, more fossils and further research are needed, which also indicates the scientific importance of amber research." (End)