Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
When former US president Donald Trump announced his decision to shrink protected areas loaded with important fossils and artefacts in the southwest United States, many palaeontologists were appalled — and even helped launch a court case to restore the lands. Now, incumbent President Joe Biden is taking steps to review the decision, which many scientists hope will lead to a restoration of the original reserves.