The picture shows the three-dimensional model of the legs and limbs of four Chengjiang arthropod species and their three-dimensional modeling renderings. The red-stained upper limbs are new to this study. Courtesy of the Institute of Paleontology of Yunnan University
Kunming, July 30 (Luo Jie) reporters learned from the Institute of Paleontology of Yunnan University on the 30th that the research team composed of researchers from the Institute of Paleontology of Yunnan University, the Natural History Museum in London, the United Kingdom, and the University of Munich in Germany, with the help of the international cutting-edge micro-CT scanning technology and computer three-dimensional restoration technology, revealed a new structure of the double-branch leg base of several arthropods in the Chengjiang biota of Yunnan Province, 518 million years ago, that is, the upper limb (or "outer lobe").
According to reports, since the discovery of the Burgess Shale Fossil Group in Canada in 1909, the international paleontological community and the evolutionary biology community have always believed that the leg type of the early Cambrian arthropod is a relatively simple double-branched type, that is, only the inner and outer limbs are attached to the original limbs. At the same time , the structure of the upper limbs is always treated differently as a characteristic unique to crustaceans ( e.g. shrimp , crabs ) and their ancestral taxa. Some studies have proposed that any arthropod with an upper limb structure is a member of the evolutionary branch of crustaceans.
Pictured here are arthropod species of the four non-crustacean clades involved in the study. Courtesy of the Institute of Paleontology of Yunnan University
After conducting in-depth research on the three-dimensional structure of the legs of four non-crustacean clades, Leachoilia obesa, Naraoia spinosa and Retifacies abnormalis (Inset 2), the international research team with the Institute of Paleontology of Yunnan University as the core conducted in-depth research on the legs and limbs of four non-crustacean clades. The above view was questioned.
The team further pointed out that the upper limb is likely to be a structure that was ubiquitous in early arthropods, rather than a feature unique to crustaceans and their ancestral taxa. The new findings in the study are an important breakthrough in the study of arthropod evolution. Previous phylogenetic work based on the morphology of the legs of early arthropods has required recoding and analysis.
The relevant research results were published in the international first-class academic journal Nature Communications "Nature Communications" on the 30th. (End)
Source: China News Network