Cynodonts are a group of therapsids that lived during the late Permian to the late Triassic periods. They are significant in the evolutionary history of mammals, as they exhibit features that are precursors to modern mammals, such as differentiated teeth and a more advanced jaw structure. These creatures are characterized by their small size and varied diets, which included both herbivorous and carnivorous species. Cynodonts are often considered a key link between reptiles and mammals, showcasing the transition from reptilian to mammalian traits over millions of years.