Captorhinomorphs are an extinct group of reptiles that belonged to the subclass Diapsida and are considered some of the earliest amniotes. They lived during the late Carboniferous to the early Triassic periods, approximately 300 to 240 million years ago. Characterized by their distinct tooth structure and robust skulls, captorhinomorphs are thought to be closely related to the ancestors of modern reptiles. Their diverse morphology suggests they occupied various ecological niches during their time.