If you look at the photographs that accompany this story, they might not tell you much: another fossil of a prehistoric creature, decently preserved. But it’s actually a scientific feat, a one-in-a-million find: What researchers have unearthed at the Chinese site in Chengjiang is an arthropod larva that lived about 520 million years ago. And, come on, it’s barely two millimeters long, like the tip of a pencil .
Apart from its dimensions and its incredible state of conservation in 3D, the importance of this fossil lies in the information it provides to paleontologists about the early stages of development of arthropods – the same group to which insects, crustaceans and arachnids belong – in the Cambrian period.
First, researchers have managed to identify the species of this primitive arthropod baby: Leanchoilia illecebrosa . And like the other members of his family, he has a segmented body. Seven pairs of legs can also be distinguished – three of them less developed -, a rear dagger-shaped appendage that may have been used for swimming, and two claw-like structures on the head .
This discovery is the result of hard and patient work in which luck also plays a role. Once the suspect was located in the rock, the scientists, led by Chinese paleontologist Yu Liu, used X-ray techniques with computerized microtomography to examine his anatomy in detail and take photos that illustrate the text. As indicated in the journal where the finding was made public, the Proceedings of the National Academy of Sciences , the study of the Leanchoilia illecebrosa fossil will serve to shed some more light on the biological explosion that took place in the Cambrian period , when they emerged in a brief period of time the main lineages of terrestrial animal life.
Photo credit: Y. Liu, R. Melzer and J. Haug
