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Neogloboquadrina pachyderma
Neogloboquadrina pachyderma (N. pachyderma) is a planktonic foraminifera that builds its shell, also known as test, with calcium carbonate. They evolved from Paragloborotalia continuosa in the late Miocene, approximately 9.4 million years ago and are widely used within paleoenvironmental reconstructions.

Geographic distribution and ecology
Neogloboquadrina pachyedrma is a typical polar species with a large abundance in the northern and southern polar regions. They live in the upper few hundred meters, 50 and 200 m, of the water column. Their distribution vary depending on sea ice cover, and physical properties such as temperature, salinity, and food availability. It has been found that their abundance are greatest in the mixed layer, upper themocline and at ice margins. Under the ice cover they are much less. They thrive in the saline cold, near-freezing sea-surface temperatures ranging from 0 to 6°C. Usually N. pachyderma are not found in salinities lower than 32 psu (practical salinity unit).

Biology
During their lifetime, N. pachyderma migrate vertically in the water column, where their fibrillar bodies may act to control buoyancy. At specific depths, often close to the pycnocline,they reproduce. Shell growth of N. pachyderma occurs by sequential addition of chambers. Pores are formed at an early stage of wall calcification, while the ridges and ornaments form simultaneously.

N. pachyderma is asymbiotic, meaning that they live independently without close association with other species.

Shell morphology
Neogloboquadrina pachyderma has a wide range of morphologies that has changed over time. However, this variation became less through Pleistocene. Typically, the test of N. pachyderma is tropchospiral, meaning that the chambers have a spiral growth pattern or coiling. The coiling can either be sinistral (left-coiling) or dextral (right-coiling) and is thought to be driven by environmental conditions such as temperature. Left-coiling tests are therefore more common in polar regions and subpolar regions while right-coiling tests mostly is found in subtropical to temperate areas. The chambers are usually four and have globular shape while the general test form is rhombic, giving N. pachyderma its popcorn-like appearance. From a ventral view (back side) the chambers of N. pachyderma has a characteristic cross-like appearance, making it distinguishable. The aperture type (primary opening of the shell) is umbilical with a narrow arch shape and a prominent lip that can be displayed on the last chamber. The walls are macroperforate non-spinose, showing smooth ridges and have relative few pores.

Applications
Due to the preservation potential of the calcareous tests of N. pachyderma, coupled with their stratigraphic significance and sensitivity to environmental stress, they are widely used for paleoenvironmental reconstructions of surface-water using asseblages and geochemical proxy studies. A specific case is using stable isotopic signals extracted from planktonic foraminifera to recognize glacial cycles. Within palaeoceanography the depth habitates of the foraminifera has been useful for tracing ocean layering, circulation and global temperature gradients. Some other examples of their applications are in stratigraphy (biostratigraphy) and correlation, dating/age modelling, the study of evolution and coupling of evolution to environmental change.