Globigerinina

Globigerinina

Illustration of a Globigerina species

Globigerinina is a suborder of foraminifera, a group of amoeboid protists characterized by their streaming granular cytoplasm and, in many species, a shell or "test". These organisms are primarily marine and are found in both planktonic and benthic environments. Globigerinina are particularly notable for their role in the marine carbon cycle and as indicators in paleoclimatology.

Morphology

Globigerinina are distinguished by their calcareous shells, which are typically composed of multiple chambers arranged in a spiral. The shells are made of calcium carbonate, and their structure can vary significantly between species. The surface of the shell may be smooth or covered with spines, which can aid in buoyancy and feeding.

Ecology

Globigerinina are predominantly planktonic, meaning they float in the water column. They are found in oceans worldwide, from the surface to deep waters. These organisms play a crucial role in the marine food web, serving as prey for a variety of marine animals, including zooplankton and small fish.

Life Cycle

The life cycle of Globigerinina includes both asexual and sexual reproduction. They reproduce asexually by binary fission, where the organism divides into two. Sexual reproduction involves the formation of gametes, which fuse to form a zygote. The zygote then develops into a new individual.

Fossil Record

Globigerinina have an extensive fossil record, dating back to the Jurassic period. Their fossilized shells are abundant in marine sediments and are used by geologists and paleontologists to date sedimentary rock layers and to reconstruct past climates. The presence of certain species of Globigerinina in sediment cores can indicate past ocean temperatures and ice volume.

Importance in Paleoclimatology

Globigerinina are valuable in the study of paleoclimatology due to their sensitivity to changes in ocean temperature and chemistry. The isotopic composition of their shells can provide information about past sea surface temperatures and ice volumes. This makes them important proxies for understanding historical climate change.

Related Pages

• Foraminifera
• Paleoclimatology
• Marine carbon cycle
• Zooplankton