A new assemblage of dabashanellids (Crustacea: Phosphatocopida) from Cambrian Stage 3 of western Hubei Province, South China

Dabashanellids are univalved phosphatocopid crustaceans, and are among the earliest crustaceans known so far. They were reported mainly from the Cambrian Stage 3 of China, but only a single species was established. Here I report a new assemblage of dabashanellids from the Cambrian Stage 3 Shuijingtuo Formation in western Hubei Province, South China. All specimens are sub-millimetre in length, and are preserved as three-dimensional carbonaceous hollow shields. Five species of Dabashanella were recognized, including the previ-ously reported D. hemicyclica, three new species, D. longa n. sp., D. semiorbiculata n. sp., D. unispinata n. sp., and an indeterminate form Dabashanella sp. In addition, five indeterminate forms of arthropods were recovered. These dabashanellids represent part of a meiofauna that lived in the off-shore, deeper environments of mid-northern Yangtze Sea during Cambrian Age 3. This study shows greater mor-phological diversity and ecologic disparity of dabashanellid crustaceans, and supports the previous suggestion that the invasion of meio-faunal ecdysozoans into the off-shore, deeper environments probably occurred simultaneously with their radiation in the shallow water.(c) 2022 Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. All rights reserved.

Automated summary

A new assemblage of dabashanellids, including five species of Dabashanella and five indeterminate forms of arthropods, has been reported from the Cambrian Stage 3 Shuijingtuo Formation in western Hubei Province, South China. These sub-millimetre-sized specimens are preserved as three-dimensional carbonaceous hollow shields and represent part of a meiofauna living in the off-shore, deeper environments of mid-northern Yangtze Sea during the Cambrian Age 3. The study reveals greater morphological diversity and ecological disparity of dabashanellid crustaceans.