Stigmaria

St Andrews is a natural laboratory for the study of sedimentary rocks like sandstones, coals and limestones, deposited in an ancient river delta.

This fossilised tree root was collected from a beach to the east of St Andrews. It gives students insights into the first tropical forests in Earth’s history, which helped supply the atmosphere’s oxygen. After they died, they were buried in the swamps of the delta to form coal.

Identified by Professor John Howard of the Western University London, Ontario.

Credit: Courtesy of the University of St Andrews Libraries and Museums