Researchers from the University of Reading and the University of York have discovered a way to use crystals found in earthworm feces to measure ancient climate temperatures.

Researchers from the University of Reading and the University of York have discovered a way to use crystals found in earthworm feces to measure ancient climate temperatures.

The chemical make up of small calcite crystal granules excreted by the nightcrawler species of worm changes depending on the temperature at the time.

The granules are about 2 millimeters and have a recognizable appearance, so they can easily be identified in the field.

Experiments show they treat acid related indigestion in the worms.

Ratios of chemical isotopes of oxygen in the earthworm feces act as a way for scientists to know the climate conditions at different levels of soil on archaeological sites.

The lead author on the paper, commented: “Earthworms secrete several each day, so they provide a record of the seasonal variations in temperature as well as local geographical variations.”

The researchers are taking samples of the earthworm feces crystals from thousands of years ago to get a picture of ancient local climate conditions.

They can then compare the results they get from the earthworm feces to other naturally occurring climate records like ice cores, tree rings, and deep ocean sediment.