nannoplankton

Biostratigraphy based on inoceramids, nannoplankton or forams is more detailed.

Ana there's the usual plankton and nannoplankton population."

Coccoliths and related fossils are referred to as calcareous nannofossils or calcareous nannoplankton.

The base of the Bartonian is at the first appearance of the calcareous nannoplankton species Reticulofenestra reticulata.

In the marine realm, the Carnian saw the first abundant occurrences of calcareous nannoplankton, a morphological group including the Coccolithophores.

The base of the Tortonian stage is at the last common appearance of calcareous nannoplankton Discoaster kugleri and planktonic foram Globigerinoides subquadratus.

Nano, with a single "n" in the middle, is a prefix meaning one-billionth, but geologists use a variant spelling in their word for the tiny ocean creatures called nannoplankton.

The base of the Serravallian is at the first occurrence of fossils of the nannoplankton species Sphenolithus heteromorphus and is located in the magnetic chronozone C5ABr.

In the Upper Jurassic the CCD was probably much higher and ranged somewhere between 2000 and 3000 meter depth due to a greatly diminished calcareous nannoplankton at that time.

The base is also close to the extinction level of the calcareous nanoplankton species Triquetrorhabdulus rugosus (the base of biozone CN10b) and the first appearance of nannoplankton Ceratolithus acutus.

In studies conducted with Carol Stephens, he showed that ultraviolet sensitivity was particularly severe among the nannoplankton (single-cells plants between 2 and 20 microns wide) and picoplankton (smaller than 2 microns; a micron is one-thousandth of a millimeter).

The gradual replacement of the radiolarian oozes of the Ruhpolding Formation by coccolith oozes of the overlying Aptychen Beds can be explained by further deepening of the basin and/or by blooming calcareous nannoplankton.

The top of the Maastrichtian stage is defined to be at the iridium anomaly at the Cretaceous-Paleogene boundary (K-T boundary), which is also characterised by the extinction of many groups of life, such as certain foraminifers and calcareous nannoplankton, all ammonites and belemnites, etc.