Biostratigraphic significance and geometric morphometrics of Euestheria gutta (Crustacea: Branchiopoda: Spinicaudata): An index fossil of continental Permian–Triassic transitional beds. (10th February 2021)

• Record Type: Journal Article
• Authors: Miao, Xue; Chu, Daoliang; Tong, Jinnan; Benton, Michael J.; Yu, Jianxin; Luo, Liang; Shu, Wenchao; Wu, Yuyang
• Other Names: Chen Zhong‐Qiang guestEditor.; Wang Xiangdong guestEditor.; Cao Cangqun guestEditor.; Luo Mao guestEditor.
• Is Part Of: Geological journal. Volume 56:Number 12(2021)
• Page Start: 6176
• Page End: 6188
• Publication Date: 2021-02-10
• Subjects: Euestheria gutta -- palaeogeographical distribution -- palaeoecology -- Permian–Triassic transition -- Spinicaudatan; Geology -- Periodicals; 551
• DOI: 10.1002/gj.4096
• Languages: English
• ISSNs: 0072-1050

Abstract

Abstract : The Permian–Triassic mass extinction was the largest biotic extinction event in the Phanerozoic and affected both marine and continental life. Marine Permian–Triassic transitional sequences can be correlated in many regions, but this has proved difficult for continental successions. A growing number of studies show that spinicaudatans are some of the most common fossils in continental strata and can be used as index fossils for continental stratigraphic division and correlation. Here we document the morphology and biostratigraphic significance of Euestheria gutta based on well‐preserved fossils from southwestern China. It shows strong intraspecific morphological variation, while the most important feature is the strongly convex larval valve and significant finely pitted to weakly reticulated ornamentation on the growth bands. Evidence from palaeobotany, charcoal, and organic carbon isotopes indicated that the continental mass extinction in southwestern China was marked by the catastrophic loss of tropical rainforest vegetation, enhanced wildfire and a negative carbon isotope excursion (CIE) during the P–Tr transition. Meanwhile, abundant E. gutta first appeared at the onset of the negative CIE and just above the horizon of the loss of macroflora. Based on the global geographic distribution of E. gutta and temporal correlation, we conclude that this species existed from the latest Permian to the earliest Triassic, and the occurrence of E. gutta could be used as an index fossil of the continental mass extinction interval or P–Tr transitional beds. Abstract : The morphology and biostratigraphic significance of Euestheria gutta is studied based on well‐preserved fossils from southwestern China. It shows the most important feature is the strongly convex larval valve and significant finely pitted to weakly reticulated ornamentation on the growth bands. Abundant E. gutta first appeared at the onset of the negative carbon isotope excursion (CIE) and just above the horizon of the loss of macroflora which indicates this species existed from the latest Permian to the earliest Triassic.