Unusually well preserved Cretaceous radiolarians are observed in the subsurface sections from two drilled sites in the Weddell Sea collected during Leg 113 of the Ocean Drilling Program. Radiolarians from the lithified calcareous chalk of Hole 689B represent the first Campanian-Maestrichtian assemblage which is characterized by abundant Cromyodruppa Iconcentrica, Dictyomitra multicostata, and Protostichocapsa stocki. Abundant Pseudodictyomitra pentacolaensis and Diacanthocapsa sp. 1, on the other hand, are the main constituents of the assemblage from the latest Aptian/earliest Albian diatomite of Hole 693B. These represent the oldest and the highest-latitude reported radiolarian occurrences from the Atlantic sector of the Antarctic Ocean. The assemblages are marked by their low diversity and an absence of low- to mid-latitude zonal indices.

Relative abundance of taxa based on population counts of two strewn microslides (with cover glass of 22 * 40 mm size): A = abundant (>26 specimens), C = common (11-25 specimens), F = few (6-10 specimens), R = rare (2-5 specimens), + = single specimen, - = absent.

Supplement to: Ling, Hsin Yi; Lazarus, David B (1990): Cretaceous radiolaria from the Weddell Sea: Leg 113 of the Ocean Drilling Program. In: Barker, PF, Kennett, JP; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 113, 353-363