The fossil is approximately 6 million years old.
According to a new report on PeerJ, scientists have unearthed the first fossil of an Amazon River Dolphin proving that the Inia geoffrensis species existed in this region 6 million years ago. The bones that have been extracted have been well-preserved and scientists were able to draw many conclusions from their study.
Inia geoffrensis species are freshwater dolphins that usually live in Amazon, Peru, Brazil, Colombia and Venezuela. They are considered endangered species particularly during the past years during which they have been the victims of pollution and excessive fishing. Amazon River Dolphins are also known as pink river dolphins because their color ranges from grey to carnation pink.
In spite of all the knowledge we possess on this species of dolphins, paleontologists have made a new discovery that could contradict everything we knew on their evolution. Scientists have recently unearthed a fossil of an Amazon River Dolphin which appears to date back to 6.1 million years ago.
The fossil was found along the Caribbean coast of Panama proving researchers that the species of dolphins still existed in sea waters back then. Previous data suggested that Amazon River Dolphins migrated towards fresh water when ocean water levels began to rise exceedingly.
According to scientists, the found bones include some skull parts, some jaw bones, teeth and fragments of the scapula. The fossils have been entirely preserved allowing researchers to estimate the age of the dolphin at approximately 5.8 – 6.1 million years.
Computer generated programs have enabled researchers to reconstruct the dolphin based on the information they have withdrawn from the fossils. Their calculations have revealed that the dolphin was 2.85 meters (9.4 feet) long, that is, slightly longer than modern species.
The skull has revealed that the muzzle of the dolphin was approximately 36-centimeter. Its form presented several differences compared to the modern species of dolphins. Researchers have reasons to believe that the snout of the fossil pointed straight forward, whereas today river dolphins have downward noses.
Further inferences could be drawn thanks to this new discovery that scientists have made about Amazon River Dolphins. In their opinion, the species lived in sea waters and consumed smaller fish due to the shape of their snout.
Scientists have concluded that the newly found fossil is either a close relative of existing species of Amazon River Dolphin or a descendant of a much older freshwater dolphin that probably moved back to the sea 6 million years ago and has not yet been discovered.