(Peer-Reviewed) First mixopterid eurypterids (Arthropoda: Chelicerata) from the Lower Silurian of South China
Han Wang 王晗 ¹ ², Jason Dunlop ³, Zhikun Gai 盖志坤 ² ⁴ ⁵, Xiaojie Lei 雷晓洁 ¹ ⁶, Edmund A. Jarzembowski ¹ ⁷, Bo Wang 王博 ¹
¹ State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210008, China
中国 南京 中国科学院南京地质古生物研究所 生物演化与环境卓越创新中心 现代古生物学和地层学国家重点实验室
² University of Chinese Academy of Sciences, Beijing 100049, China
中国 北京 中国科学院大学
³ Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin 10115, Germany
⁴ Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Palaeontology and Palaeoanthropology, Chinese Academy of Sciences, Beijing 100044, China
中国 北京 中国科学院古脊椎动物与古人类研究所 脊椎动物演化与人类起源重点实验室
⁵ Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Beijing 100044, China
中国 北京 中国科学院生物演化与环境卓越创新中心
⁶ University of Science and Technology of China, Hefei 230026, China
中国 合肥 中国科学技术大学
⁷ Department of Earth Sciences, Natural History Museum, London SW7 5BD, UK
Eurypterids, or sea scorpions, are an important group of midPaleozoic chelicerate arthropods whose evolution and palaeoecological significance have attracted much attention in recent years. One of the most remarkable eurypterid families is Mixopteridae, whose members are quite large and superficially scorpion-like eurypterids bearing highly specialized anterior appendages. Their second, and especially the third, pair of prosomal limbs are enlarged and very spiny. These limbs were presumably used for prey-capture, and analogies can be drawn with the 'catching basket, formed by the spiny pedipalps of whip spiders (Amblypygi) among the arachnids.
Our knowledge of these bizarre animals is limited to only four species in two genera described 80 years ago: Mixopterus kiaeri from Norway, M. multispinosus from New York, M. simonsoni from Estonia, and Lanarkopterus dolichoschelus from Scotland; all are Silurian in age and come exclusively from the palaeocontinent of Laurussia, which constrains our knowledge of the morphological diversity, geographical distribution and evolutionary history of the group. Here, we describe a new mixopterid, Terropterus xiushanensis gen. et sp. nov., from the Lower Silurian (Llandovery) Xiushan Formation of Xiushan, characterized by a unique arrangement of spines on prosomal limb III; and two incomplete, but larger fossils (Terropterus sp.) from the Lower Silurian (Llandovery) Fentou Formation of Wuhan in Hubei Province. These discoveries represent the first mixopterids from Gondwana and the oldest known mixopterids, and thus add to our knowledge of mixopterid orphological diversity and geographical distribution.