Foraminifera are an amazing group of animals. Despite their microscopic size, they have had a large impact on our understanding of climate and ocean history. Studying the diversity of Foraminifera, their abundance, and complex morphology, scientists have been able to write crucial theories pertaining to paleoclimatology and paleoceanography. The oxygen isotopes of their tests indicate past climatic conditions. In addition, their speciation and age in the fossil record provide a record of past ocean depths and conditions as certain species occupy particular depths and temperatures. The relationship Foraminifera have with special oceanic environments has made their study a useful tool in locating and extracting hydrocarbons.