PINK DOLPHINS ANCESTORS
Ancestors of Inia geoffrensis were a relatively successful marine group, but were displaced during the Miocene period by the appearance of more advanced delphinids. Inia may have entered the Amazon from the Pacific Ocean approximately 15 million years ago, or from the Atlantic Ocean between 1.8 million and 5 million years ago. Their long beaks (often lined with tiny hairs), small eyes, disproportionately large flippers and highly flexible bodies -- once considered "primitive" features -- are now recognized as specialized adaptions to a complex environment.
Soltalia fluviatlis is a warm-water coastal species distributed from the eastern coast of Central America down along the northeastern coast of South America. No one knows for sure when some of these delphinids began to occupy and adapt to freshwater river systems. They are one of the few delphinid species which can move freely between fresh, brackish, and marine waters.