Earliest occurrence of lophogastrid mysidacean arthropods (Crustacea, Eucopiidae) from the Anisian Luoping Biota, Yunnan Province, China

Abstract

Abstract.-Tiny, pelagic arthropods from the Anisian Luoping Biota exposed in two quarries near Luoping, Yunnan Province, China, represent the numerically most abundant organisms in the assemblage. They form the basis for definition of two, and possibly three, species referred to the order Lophogastrida, family Eucopiidae. Yunnanocopia grandis new genus new species and Y. longicauda n. gen. new species represent the oldest occurrence of mysidaceans in the fossil record. Their anatomy allies them with the Ladinian species Schimperella acanthocercus Taylor, Schram, and Shen, 2001, from Guizhou Province, China, which previously was thought to be the oldest lophogastrid, and with extant species of Eucopiidae. Their appearance in the Anisian represents one additional element of the early faunal radiation within the Luoping Biota following the end-Permian extinction event. Presence of well-preserved oostegites, along with other morphological features, documents a conservative bauplan expressed in Eucopiidae.

After 100 years: a detailed view of an eumalacostracan crustacean from the Upper Jurassic Solnhofen Lagerstätte with raptorial appendages unique to Euarthropoda

“…Representatives of Mysidae (large ingroup of Mysida) possess a statocyst, a balance organ, in the proximal part of the endopods of the uropods (Wittmann et al 2014). The lack of this character has been used to separate lophogastridans from mysidans (Meland et al 2015;Feldmann et al 2017). However, this character alone only helps to exclude a species or specimen from being an ingroup of Mysidae.…”

“…At least six fossil species have been interpreted as representatives of Eucopiidae: Schimperella beneckei Bill, 1914, Schimperella kessleri Bill, 1914, Schimperella accanthocercus Taylor, Schram & Yan-Bin, 2001, Yunnanocopia grandis Feldmann, Schweitzer, Hu, Huang, Zhou, Zhang, Wen, Xie, Schram, Jones, 2017, Yunnanocopia longicauda Feldmann, Schweitzer, Hu, Huang, Zhou, Zhang, Wen, Xie, Schram, Jones, 2017, andEucopia praecursor Secretan &Riou, 1986. Yet, all these fossils do not clearly possess apomorphies of the group, but are characterized by plesiomorphies.…”

“…Yunnanocopia grandis and Yunnanocopia longicauda were both described from the Anisian (~245 Ma, Middle Triassic) of China (Feldmann et al 2017). Unfortunately, thoracopods are not preserved in any of the two species.…”

A new Ladinian (Middle Triassic) mysidacean shrimp (Crustacea, Lophogastrida) from northern Italy and southern Switzerland

“…More recently, Feldmann et al (2017) reported lophogastrid mysidaceans from the late Anisian Luoping Fauna (Member II of the Guanling Formation), Yunnan Province, where Fu et al (2010) and Feldmann et al (2012) previously described, respectively, Isopoda and Decapoda. Feldmann et al (2017) described a new genus, Yunnanocopia , with two new species, Y. grandis and Y. longicauda , and a third possible new species was left in open nomenclature.…”

A new mysid (Crustacea, Mysida) from the Ladinian Stage (Middle Triassic) of Conca de Barberà (Catalonia, NE Iberian Peninsula)

“…This key process in the evolution of life ended with the replacement of the "Palaeozoic Fauna" with the "Modern Fauna" (Sepkopski, 1984;Márquez-Aliaga, 2010;Escudero-Mozo et al, 2015). Between recognized biotic elements of the Middle Triassic, "mysidaceans" were one of the dominant components with a probably high abundance in some geographical areas (Feldmann et al, 2015(Feldmann et al, , 2017.…”