{"title":"New artiopodan euarthropods from the Chengjiang fauna (Cambrian Stage 3) at Malong, Yunnan, China","authors":"Yuyan Zhu, Han Zeng, Yao Liu, Fangchen Zhao","doi":"10.4202/app.01080.2023","DOIUrl":null,"url":null,"abstract":"The artiopodans, consisting of trilobites and their relatives, were a major euarthropod group in the Paleozoic. Since the first discovery of Naraoia from the Chengjiang fauna, a significant number of artiopodans have been subsequently found in China. Here we describe three new artiopodan species from the lower Cambrian Chengjiang fauna (Cambrian Series 2, Stage 3) at Malong, Yunnan, China. Zhugeia acuticaudata gen. et sp. nov. is defined by a semielliptical cephalon with long genal spines, nine overlapping thoracic tergites, and a pygidium with an elongated needle-like median spine. Its cephalic shield covers multiple anterior thoracic tergites. Tonglaiia bispinosa gen. et sp. nov. is defined by a suboval cephalon, seven thoracic tergites, and a micropygous pygidium with a pair of parallel posteriormost spines. Sidneyia malongensis sp. nov., a new occurrence of Sidneyia from South China, is defined by a crescent-shaped cephalon, eight imbricated tergites, and an abdomen consisting of two cylindrical segments and a tail fluke. The evolutionary affinities of these new taxa are reconstructed and discussed in a phylogenetic context. Phylogenetic analyses resolve Z . acuticaudata among the xandarellids and T . bispinosa gen. et sp. nov. as a trilobitomorph with an uncertain placement, The discovery of three new species improves the biodiversity of artiopodans from the Cambrian and the Chengjiang fauna","PeriodicalId":50887,"journal":{"name":"Acta Palaeontologica Polonica","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Palaeontologica Polonica","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4202/app.01080.2023","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PALEONTOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The artiopodans, consisting of trilobites and their relatives, were a major euarthropod group in the Paleozoic. Since the first discovery of Naraoia from the Chengjiang fauna, a significant number of artiopodans have been subsequently found in China. Here we describe three new artiopodan species from the lower Cambrian Chengjiang fauna (Cambrian Series 2, Stage 3) at Malong, Yunnan, China. Zhugeia acuticaudata gen. et sp. nov. is defined by a semielliptical cephalon with long genal spines, nine overlapping thoracic tergites, and a pygidium with an elongated needle-like median spine. Its cephalic shield covers multiple anterior thoracic tergites. Tonglaiia bispinosa gen. et sp. nov. is defined by a suboval cephalon, seven thoracic tergites, and a micropygous pygidium with a pair of parallel posteriormost spines. Sidneyia malongensis sp. nov., a new occurrence of Sidneyia from South China, is defined by a crescent-shaped cephalon, eight imbricated tergites, and an abdomen consisting of two cylindrical segments and a tail fluke. The evolutionary affinities of these new taxa are reconstructed and discussed in a phylogenetic context. Phylogenetic analyses resolve Z . acuticaudata among the xandarellids and T . bispinosa gen. et sp. nov. as a trilobitomorph with an uncertain placement, The discovery of three new species improves the biodiversity of artiopodans from the Cambrian and the Chengjiang fauna
期刊介绍:
Acta Palaeontologica Polonica is an international quarterly journal publishing papers of general interest from all areas of paleontology. Since its founding by Roman Kozłowski in 1956, various currents of modern paleontology have been represented in the contents of the journal, especially those rooted in biologically oriented paleontology, an area he helped establish.
In-depth studies of all kinds of fossils, of the mode of life of ancient organisms and structure of their skeletons are welcome, as those offering stratigraphically ordered evidence of evolution. Work on vertebrates and applications of fossil evidence to developmental studies, both ontogeny and astogeny of clonal organisms, have a long tradition in our journal. Evolution of the biosphere and its ecosystems, as inferred from geochemical evidence, has also been the focus of studies published in the journal.