Tiny but terribly important
Many of the organisms on Earth are so small that you need a microscope to appreciate them individually. However, some that are individually small have contributed significantly to the Earth’s structure.
Corals live in colonies that build a hard protective structure around themselves. Reefs around tropical islands are almost entirely built by corals.
Similarly, the ancient remains of foraminifera shells formed deep deposits on the sea bed. These deposits are recognised today as beds of chalk. The chalk cliffs, with bands of flint, that can be seen near Beer in South Devon are largely made from these tiny animal shells.
Sponges and diatoms
Sponges and diatoms are extremely abundant creatures in the open oceans. They use a glass-like substance to encase themselves or to form the framework for a colony. Millions of years after their deaths their remains can form flint rocks.
Radiolarians also form part of the marine plankton. When they die their skeletons sink to the bottom and form ‘radiolarian ooze’.
Preserving these tiny organisms
Individual radiolarians, diatoms and others are so tiny that scientists and collectors have preserved them on glass microscope slides. Sometimes these slides are just simple spreads of organisms. Others are works of art where the organisms have been arranged in intricate and beautiful patterns.