The reptile Macroleter: First vertebrate evidence for correlation of UpperPermian continental strata of North America and Russia

The spectacular evolutionary history of terrestrial vertebrates is uncharac teristically poorly documented between the Paleozoic subequatorial exposure s of the Permo-Carboniferous of North America and Europe, and the much high er latitude, Upper Permian deposits of central Russia and southern Africa. We report here that the discovery of the reptile Macroleter in Oklahoma pro vides the first direct vertebrate evidence of biochronological correlation between continental sediments from the Upper Permian of North America and R ussia. The presence of the reptile Macroleter, a member of a major group of Upper Permian amniotes known previously only from central Russia, in North America improves dramatically our understanding of this early phase of amn iote evolution, and also provides evidence of terrestrial tetrapod faunal i nterchange between North America and Russia in Late Permian time.