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

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 wellpreserved 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.

Late Palaeozoic‐Mesozoic palaeontology and stratigraphy in China: A tribute to the achievements of Professor Zhuoting Liao

“…Six papers report various fossil groups (bivalves, corals, and plants) (F. Chen, Xue, Yan, & Meng, 2021; Wan, Yang, Wang, Liu, & Wang, 2021; X. Wang, Yao, & Wang, 2021), trace fossils (Ding, Duan, Wu, & Cao, 2021), and carbon isotopic chemostratigraphy of the Permian (Q. Ma, et al, 2021; Wei, Tang, Gu, Fu, & Zhang, 2021). Four papers focus on biotic, palaeoecological, and environmental variations across the Permian–Triassic (P‐Tr) boundary (Cui & Cao, 2021; Miao et al, 2021; Sun et al, 2021; H. Wu, Zhang, & Sun, 2021). Two papers (X. Shi, Lang, et al, 2021; H. Yang, Chen, Mei, & Sun, 2021) and one paper (Z. Ma, Hu, et al, 2021) concerns the Early Triassic palaeoecology and Middle Triassic palaeoenvironments, respectively.…”

“…Regionally, five papers concern biosedimentary and fossil records, with one each from Henan, Hubei, Jiangxi, Zhejiang, and Inner Mongolia provinces, respectively (Bai et al, 2021; Mao et al, 2021; Sun et al, 2021; M. Wang et al (2021); Wei et al, 2021). Two papers document fossil records from Hainan and Guizhou provinces, respectively (Lan et al, 2021; Miao et al, 2021; H. Wu et al, 2021; Yao et al, 2021), and three papers each from Yunnan and Tibet provinces, respectively (Q. Chen, Chen, et al, 2021; Y. W. Li et al, 2021; Z. Ma, Hu, et al, 2021; Qiao et al, 2021; H. Shen et al, 2021; X. Wang et al, 2021). Six and seven papers address sedimentary and palaeontology of Guangxi and northern Xinjiang Province, respectively (F. Chen, Xue, et al, 2021; Cui & Cao, 2021; Z. Guo, Chen, Harper, & Huang, 2021; W. Guo, Nie, Lu, et al, 2021; X. Huang, Wang, et al, 2021; Q. Ma, Ye, et al, 2021; X. Shi, Lang, et al, 2021; T. M. Shi, Li, et al, 2021; Song et al, 2021; Wan et al, 2021; Wang F. et al, 2021; Wei et al, 2021; Zong et al, 2021; Figure 1).…”

“…Regional distribution of 30 papers assembled in the present special volume. Codes for contributions assembled in this volume: 1 = M. Wang, Guo, et al (2021); 2 = Q. Chen, Chen, et al (2021); 3 = H. Wang, Lei, et al (2021); 4 = W. Guo, Nie, Lu, et al (2021); 5 = Bai et al (2021); 6 = Qiao et al (2021); 7 = Song et al (2021); 8 = Zong et al (2021); 9 = Yao et al (2021); 10 = W. Guo, Nie, Lu, et al (2021); 11 = Tang et al (2021); 12 = Shi et al (2021); 13 = Mao et al (2021); 14 = X. Huang, Wang, et al (2021); 15 = F. Chen, Xue, et al (2021); 16 = Q. Ma, Ye, et al (2021); 17 = Wei et al (2021); 18 = Ding et al (2021); 19 = Wan et al (2021); 20 = Wang, Yao, & Wang (2021); 21 = Cui and Cao (2021); 22 = Miao et al (2021); 23 = H. Wu et al (2021); 24 = Sun et al (2021); 25 = H. Yang et al (2021); 26 = Shi et al (2021); 27 = Z. Ma, Hu, et al (2021); 28 = H. Shen et al (2021); 29 = Y. W. Li et al (2021); 30 = Lan et al (2021)…”

“…Wei, Tang, Gu, Fu, & Zhang, 2021). Four papers focus on biotic, palaeoecological, and environmental variations across the Permian-Triassic (P-Tr) boundary (Cui & Cao, 2021;Miao et al, 2021;Sun et al, 2021;H. Wu, Zhang, & Sun, 2021).…”

“…Regionally, five papers concern biosedimentary and fossil records, with one each from Henan, Hubei, Jiangxi, Zhejiang, and Inner Mongolia provinces, respectively (Bai et al, 2021;Mao et al, 2021;Sun et al, 2021;; Wei et al, 2021). Two papers document fossil records from Hainan and Guizhou provinces, respectively (Lan et al, 2021;Miao et al, 2021;H. Wu et al, 2021;Yao et al, 2021), and three papers each from Yunnan and Tibet provinces, respectively (Q.…”