SummaryA poster from the 2012 Holiday Lectures on Science, Changing Planet: Past, Present, Future. It details the importance of foraminifera, known as "forams" for short, in discovering significant changes in Earth's past.
The word "foram" is short for foraminifera, a class of single-celled microorganisms known as protists. They first appeared in the rock record about 540 million years ago. Today, most forams range in size from 0.1 to 1 mm, but in the geologic past, forams have been as big as 20 cm. Forams are important for their roles as timekeepers of geologic age, as indicators of mass extinction and climate changes, and as pollution monitors. This poster describes these roles and illustrates forams' many shapes and sizes.