A commonly-held belief for many years - that 90 million years ago, a continental ice sheet formed during the Late Cretaceous Period - is now looking to be false.
New research from the University of Missouri analysed fossilised shells of 90 million year old single-celled organisms, about the size of a grain of salt. Measuring the ratios of different isotopes of oxygen and carbon in the fossils gives scientists information about past temperatures and other environmental conditions.
This discovery could help to predict what Earth’s climate will be as carbon dioxide levels continue to rise.
Read more at University of Missouri