The dusty Pisco-Ica desert stretches along the coast of southern Peru, but more than 16 million years ago it may have been covered with sparkling water and home to a now-extinct family of dolphins, known as squalodelphinids, according to new findings.
The desert is a haven for marine fossil hunters â€” paleontologists have found whales with fossilized baleen, a giant raptorial sperm whale and a dolphin that resembles a walrus, researchers say.
The new findings include the fossils of three dolphins, two of which have well-preserved skulls. A thorough skeletal analysis suggests the dolphins are not only a new species but also related to the endangered South Asian river dolphins living in the Indus and Ganges rivers in India today, the researchers found.
“The quality of the fossils places these specimens as some of the best-preserved members of this rare family,” lead study author Olivier Lambert, of the Institut Royal des Sciences Naturelles de Belgique, said in a statement.
River dolphins are an unusual breed. Unlike other dolphins, they live in muddy freshwater rivers and estuaries, and they have a long, narrow, toothy beak and small eyes with poor vision, said Jonathan Geisler, an associate professor of anatomy at the New York Institute of Technology, who was not involved in the study.
The three fossils do not appear to be ancestors of other river dolphins, including those of the Amazon or the Yangtze rivers, the latter of which may be extinct, said John Gatesy, an associate professor of biology at University of California, Riverside, who was not involved in the study.