Early Paleogene dinoflagellate cysts from ODP Hole 959D, Côte d'Ivoire-Ghana Transform Margin, West Africa: New species, biostratigraphy and paleoenvironmental implications

• Five biostratigraphic zones were proposed for the Paleocene-Eocene interval of ODP Hole 959D.
• An outer neritic to oceanic environment was inferred based on the abundances of typically offshore dinoflagellate cysts.
• Four new dinoflagellate cyst species were identified.

A nearly continuous sedimentary record from Ocean Drilling Program (ODP) Site 959 (Hole 959D) in the Côte d’Ivoire-Ghana Transform Margin provides the opportunity to study Lower Paleogene palynology in this equatorial region. This paper presents data for 117 dinoflagellate cyst taxa recorded in 18 samples covering a 91-m interval from 867.60 mbsf to 776.32 mbsf. Preservation of dinoflagellate cysts varied from poor to excellent, and recovery was almost superabundant. Based on last or first occurrence of dinoflagellate cyst events, five zones (zone 1 to zone 5) were identified. The concentration of several dinoflagellate cyst events in the Thanetian interval suggests the presence of hiatuses or condensed horizons as inferred in previous studies of nearby localities. Frequent to common abundance of Apectodinium in the upper Thanetian sediments apparently records the global episodes of intense climatic warming that characterized the latest Paleocene to earliest Eocene time. An assemblage dominated by species of Operculodinium, Spiniferites, and Tectatodinium confirms the outer neritic to oceanic depositional setting of the drill hole as previously inferred from lithologic characteristics. Finally, four new dinoflagellate cyst taxa, Adnatosphaeridium ivoriense, Diphyes digitum, Eocladopyxis furculum and Tectatodinium nigeriaense that were observed only in the Paleocene interval, have been formally identified and described in detail.