A Review of Palaeozoic Conodont Researches in Mongolia

Since the beginning of 1960s, Palaeozoic strata have been identified in Mongolia, and their subdivision and correlation were discovered by Mongolian-Soviet Paleontological Joint Expedition. The conodont research played an important role in determining the key chronostratigraphic boundary and the regional stratigraphic units in favor of the establishment of stratigraphy of Mongolia and understanding the tectonic evolution of the Central Asian Orogenic Belt (CAOB). This review paper synthesizes conodont research conducted in Mongolia between 1977 and 2025, documenting their occurrences across 29 formations (1 in Cambrian,4 in Ordovician, 3 in Silurian, 16 in Devonian, 2 in Carboniferous, and 3 in Permian). A total of 182 conodont species belonging to 53 genera have been identified from these strata. The Cambrian Period marks a significant evolutionary event with the diversification of animals. The lower Cambrian Bayangol Formation yields protoconodonta Mongolodus rostriformis Missarzhevsky, 1977,Protohertzina unguliformis Missarzhevsky, 1977 and Protohertzina anabarica Missarzhevsky, 1973 fromsouthwestern Mongolia. Ordovician conodonts have been known from four formations: Chigertei, Tsagaan Del, Onoo Tolgoi and Khuuvur. Silurian conodonts have been identified from the Gavuu Member of the Mandal-Ovoo Formation in the Mushgai area and the upper Zalaa and lower Sharchuluut formations in the Shine Jinst area. The 22 conodont biozones of Devonian and Carboniferous age (12 in the Devonian and 10 in the Carboniferous) have been established within the territory of Mongolia, providing an important foundation for regional biostratigraphic correlation. The Devonian period is exceptionally well-represented, with 124 species from 25 genera, reflecting explosion of diversity as well as extensive research on this interval. Permian conodonts are not well known in Mongolia. Permian conodonts were recorded from the Lugiingol Formation (Wang and Ariunchimeg, 2006). This review highlights key taxonomic discoveries, including index and new species, and outlines future research directions, emphasizing the need for expanded sampling in underexplored formations and integration with other stratigraphic proxies.