This list of the Mesozoic life of Wyoming contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Wyoming and are between 252.17 and 66 million years of age.
^Johnson, Kirk. (2002). Megaflora of the Hell Creek and lower Fort Union Formations in the western Dakotas: Vegetational response to climate change, the Cretaceous-Tertiary boundary event, and rapid marine transgression. 10.1130/0-8137-2361-2.329.