Discovery of diverse Pectocaris species at the Cambrian series 2 Hongjingshao formation Xiazhuang section (Kunming, SW China) and its ecological, taphonomic, and biostratigraphic implications

Changfei Jin; Hong Chen; Huijuan Mai; Xianguang Hou; Xianfeng Yang; Dayou Zhai

doi:10.7717/peerj.17230

Discovery of diverse Pectocaris species at the Cambrian series 2 Hongjingshao formation Xiazhuang section (Kunming, SW China) and its ecological, taphonomic, and biostratigraphic implications

PeerJ. 2024 Apr 15:12:e17230. doi: 10.7717/peerj.17230. eCollection 2024.

Authors

Changfei Jin^#^{1

2}, Hong Chen^#³, Huijuan Mai^{1

2}, Xianguang Hou^{1

2}, Xianfeng Yang^{1

2}, Dayou Zhai^{1

2}

Affiliations

¹ Yunnan Key Laboratory for Palaeobiology, Institute of Palaeontology, Yunnan University, Kunming, China.
² MEC International Joint Laboratory for Palaeobiology and Palaeoenvironment, Yunnan University, Kunming, China.
³ School of Biological Sciences and Technology, Liupanshui Normal University, Liupanshui, China.

^# Contributed equally.

Abstract

Pectocaris species are intermediate- to large-sized Cambrian bivalved arthropods. Previous studies have documented Pectocaris exclusively from the Cambrian Series 2 Stage 3 Chengjiang biota in Yu'anshan Formation, Chiungchussu Stage in SW China. In this study, we report Pectocaris paraspatiosa sp. nov., and three other previously known Pectocaris from the Xiazhuang section in Kunming, which belongs to the Hongjingshao Formation and is a later phase within Cambrian Stage 3 than the Yu'anshan Formation. The new species can be distinguished from its congeners by the sparsely arranged endopodal endites and the morphologies of the abdomen, telson, and telson processes. We interpret P. paraspatiosa sp. nov. as a filter-feeder and a powerful swimmer adapted to shallow, agitated environments. Comparison among the Pectocaris species reinforces previous views that niche differentiation had been established among the congeneric species based on morphological differentiation. Our study shows the comprehensive occurrences of Pectocaris species outside the Chengjiang biota for the first time. With a review of the shared fossil taxa of Chengjiang and Xiaoshiba biotas, we identify a strong biological connection between the Yu'anshan and Hongjingshao Formations.

Keywords: Arthropod; Hongjingshao formation; Niche differentiation; Pectocaris paraspatiosa; Xiazhuang assemblage.

Publication types

Review

MeSH terms

Animals
Arthropods* / anatomy & histology
Biota
Bivalvia*
China
Fossils

Grants and funding

This work was supported by the Yunnan Provincial Grants (Nos. 202101AT070158, 202305AB350006, 202301AS070049, YNWR-QNBJ-2019-295), the “Open for collaboration” grant from Yunnan Key Laboratory for Palaeobiology, Yunnan University and High-Level Talents of Liupanshui Normal University (No. LPSSYKYJJ202210), and Yunnan Science & Technology Champion Project 202305AB350006. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.