Middle Triassic radiolarians from the Dolomites, Southern Alps, Italy

In this paper, the taxonomy, biostratigraphy and stratigraphic range of Late Anisian (Illyrian) to Ladinian (Fassanian-Longobardian) radiolarians are examined from three continuous successions of the “Buchenstein Beds” (Livinallongo Formation) from the Seceda area, Dolomites in Northern Italy. The investigated sections contain well-preserved and diverse radiolarian assemblages, with 76 genera and 180 species, including one new genus and 18 new species. The richest and well-preserved radiolarian horizon belongs to the transition between the Spongosilicarmiger transitus and Spongosilicarmiger italicus Radiolarian Zones. This horizon is equivalent in age to the Reitziites reitzi Ammonoid Zone (Reitzi Subzone to Avisianum Subzone) and Paragondolella? trammeri Conodont Zone. This study provides new insights into the stratigraphic ranges of 180 species. The revisions to stratigraphic ranges indicate that the late Anisian (Illyrian) had a higher diversity of radiolarians than previously reported.