WANG M，FENG K J，QI Y A. Systematic revision and classification of Bifungites Desio, 1940 [J]. Journal of Henan Polytechnic University( Natural Science), doi: 10.16186/j.cnki.1673-9787.2024120063.

DOI: 10.16186/j.cnki.1673-9787.2024120063

Received：2024-12-25

Revised：2025-02-26

Online：2025-07-23

Systematic revision and classification of Bifungites Desio, 1940 (Online)

Wang Min^1，2，Feng Kejia¹，Qi Yongan¹

(1.School of Resources and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China；2.State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS, Nanjing 210000, Jiangsu, China)

Abstract: Objectives Bifungites Desio, 1940 is one of the oldest trace fossils, and its unique dumbbell shape is an important hint of the behavioral evolution of early metazoans. The characteristic morphological changes at both ends of the dumbbell-shaped structure and the relatively concentrated stratigraphic distribution make it one of the few ichnofossils with chronostratigraphic significance. However, there is no uniform classification scheme and identification standard for the nomenclature of Bifungites, which hinders its application in paleoecology and stratigraphy. Methods According to the definition and morphological interpretation of the ichnospecies of Bifungites, the original description and plates of the 11 available ichnospecies are re-identified, and the related literatures of Bifungites are collected. All reported Bifungites are systematically revised. Results Bifungites are dumbbell-shaped at the bottom. It is composed of enlarged chambers at both ends that are connected by slender tunnels. In vertical cross-section, the chambers are connected to the surface by vertical pipes, contributing to U-shaped or inverted ‘π’-shaped burrows. There are different terminal shapes of the dumbbell shape among the ichnospecies, and the terminal morphological characteristics are used as the main basis for the identification of the ichnospecies, and finally 5 valid ichnospecies are retained. They are: Bifungites cruciformis Muniz, 1982 with cross-shaped or three-lobed chambers; Bifungites fezzanensis Desio, 1940 with hemispherical or short rod-shaped chambers; Bifungites halli Desio, 1940 with spherical or subspherical chambers; Bifungites munizi Agostinho, Viana, & Fernandes, 2004, in which the two end chambers are different in shape and size; and Bifungites piauiensis Agostinho, Viana, & Fernandes, 2004 with arrow-shaped chambers. Conclusions The systematic classification and identification of Bifungites and the redefinition of published materials will help to explore the morphological and behavioral significance of Bifungites and improve its application in chronostratigraphy.

Key words：Bifungites；ichnofossil；dumbbell-like ichnofossil；revision of genera and species；morphology

CLC: Q911.28