You know spiders, scorpions
What did our ancestors look like 520 million years ago?
On May 1, according to Yunnan University, a Sino-German research team used advanced micro-CT scanning, 3D modeling and virtual dissection technology to restore the appearance of the long-tailed mantis insect in the Chengjiang biota of the Early Cambrian period 520 million years ago. The results were recently published in the internationally renowned biology journal BMC Biology.
Photo of a long-tailed mantis fossil by Zhou Guixian
According to researcher Liu Yu, team leader and deputy dean of the Institute of Paleontology of Yunnan University, there is a special branch in the Early Cambrian arthropods about 520 million years ago, and their first pair of appendages is not the antennae common to the heads of arthropods such as centipedes, but a pair of strong large appendages used for predation. Therefore, they are also known as large appendicular arthropods, and the long-tailed mantis is a type of large appendicular arthropod.
In the past, due to the lack of fossils and technical limitations, researchers have debated the evolution of this type of arthropod. In order to solve this problem, the team of Liu Yu and Hou Xianguang from the Institute of Paleontology of Yunnan University used micro-CT scanning, 3D modeling and virtual dissection technology to extract information from the surface and interior of the fossil of the long-tailed mantis insect and obtained a three-dimensional three-dimensional picture of the animal.
CT 3D model of long-tailed mantis photo courtesy of interviewee
Long-tailed mantis computer 3D modeling renderings Courtesy of the interviewee
The CT 3D model clearly shows that the elongated trunk of the long-tailed mantis is composed of 13 segments, with a long rod-shaped tail and fine spines at the ends. It is worth mentioning that the head has 6 segments, namely anterior bone fragments with a pair of stalk-like compound eyes, segments with a pair of large appendages, and 4 segments with a pair of bifacularity appendages each. Studies have shown that the two-branched appendages of the long-tailed mantis are composed of an inner limb tapering distally and a flaky outer limb with bristles at the margins, with a small outer lobe attached to the base of the basal ganglia.
"By seeing the whole picture of the long-tailed mantis, we also speculated that the large appendiced arthropods were probably the ancestors of chelera, such as spiders and scorpions. Liu Yu said.
Written by: Yue Ranran
Source: Xinhua News Agency