Tuesday, August 10, 2010

Globorotalia truncatulinoides

Globorotalia truncatulinoides (d'Orbigny, 1839) is a planktic foraminifera.

It tolerates a broad range of sea surface temperatures and salinities and occurs in subtropical and transitional water masses. It is a deep-dwelling species which ascends to shallower depths during its reproduction period in winter. In the fossil record it is since the Pleistocene and may be used for studies on climate change of the last 2 mya.

The relative abundance of dextral coiling is higher at lower latitudes.

The specimens shown here are from a sample from the Hebridian Slope off Scotland in the North Atlantic. Northwest of the British Isles, this steep continental slope to depths greater than 2000 m separates the distinct continental shelf of Europe from the deeper Atlantic Ocean. The sample is in the repository of the Scottish Association for Marine Sciences, Oban.

see more foraminifera found at the Hebridian Slope

Umbilical view of a
dextral coiling specimen

Spiral View

more images of Globorotalia truncatulinoides at
Laboratório de Microfósseis Calcários,
Rio Grande do Sul, Brasil