Explain why forams have such a well-preserved fossil record.

The supergroup SAR of the eukaryotic phylogeny has three sub-groups, Rhizarians being one of them. Some members of this group are flagellated, while some have pseudopodia; these members are further divided into three groups.

The cerozoans, forams, and radiolarians are the three groups under rhizarians, and each has a distinct morphological characteristic.

The understanding of evolution and organisms that dominated different time zones is mainly for the study of fossil remains. Fossils are preserved remains of ancestral organisms, their body parts, or an impression of their body shape, which depicts the biological diversity of historic age.

The body structure of organisms plays a vital role in fossilization and preservation of the fossilized structure.

Forams are unicellular protists that have porous body structures enclosed within hard covering (tests).The tests of forams are composed of calcium carbonate, which provides rigidity to the shell.

The hardness of the outer tests accounts for better preservation of the foramen fossils, and thus, these organisms have a well-preserved record of fossils.