A new bivalved arthropod from the Cambrian (Stage 3) Qingjiang biota expands the palaeogeographical distribution and increases the diversity of Tuzoiidae

Abstract

Fossil Lagerstätten similar to the Cambrian Burgess Shale have a crucial role in revealing the origin and early evolution of arthropods. Tuzoiidae, one of the most important groups of bivalved arthropods, occupied an important ecological niche in the Cambrian marine ecosystem. We describe a new taxon, Duplapex anima gen. et. sp. nov., in the Family Tuzoiidae on the basis of four exceptionally preserved specimens from the early Cambrian (Stage 3) Qingjiang biota of Hubei, South China. Duplapex is characterized by an ornamented bivalved carapace, a ventral notch and doublure spine on the valve and a pair of compound eyes connected by fleshy annulated eye stalks. Despite having an unusual morphology for the group, the new taxon is recognized as a tuzoiid arthropod and indicates that these problematic euarthropods had a greater degree of morphological disparity than previously considered. D. anima, as well as the newly reported Tuzoia. sp. from the Fandian biota, represent the oldest occurrence of Tuzoiidae, extending its stratigraphic range to Cambrian Stage 3 and expanding the palaeogeographical distribution of the group to the northern border of the Yangtze Platform.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosion