Calcareous nannofossil genus Scyphosphaera: structure, taxonomy, biostratigraphy, and phylogeny

摘要

Scyphosphaerids are frequently encountered in low-latitude Miocene-Pliocene sediments. The genus first evolved in the early Eocene (calcareous nannofossil Zone NP12), but abundance and diversity remained low until middle Miocene Z0nes NN5-NN6, when global radiation began. More new species (24) evolved during the Miocene NN5-NN6 and NN9 zonal intervals than at any other time. The abundance acme for the genus is the late Miocene (NN9)-late Pliocene (NN15) interval. Diversity peaked in early Pliocene Zones NN12 and NN13, with 31 extant species.