Stable oxygen analysis of Cloverly vertebrate fossils

This dataset includes stable oxygen isotope (δ¹⁸O_phosphate) measurements from 112 fossil vertebrate specimens recovered from a microfossil bonebed in the Cloverly Formation (Carbon County, Montana), which dates to the mid-Cretaceous (Aptian–Albian). The specimens represent multiple vertebrate taxa, including aquatic, semi-aquatic, and terrestrial forms. Each record includes taxonomic identification, specimen number, skeletal element sampled, and δ¹⁸O_phosphate values reported in ‰ VSMOW.