A well-preserved juvenile skull recently discovered in Ecuador belongs to a new species of ancient dolphin, which researchers are calling Urkudelphis chawpipacha. The fossil was discovered near Montañita in Santa Elena Province, a tropical region of Ecuador, and is believed to be between 24 to 26 million years old. The research has been published in the open-access journal PLOS One.
This is one of a few examples of ancient dolphin remains to be found in the tropics (the majority have been unearthed in more temperate regions like South Carolina, Oregon, Hokkaido, and New Zealand) and the very first to be found in Ecuador.
Researchers have dated the skull to the Oligocene Epoch, an era that lasted between 33.9 and 22 million years ago. During this period, the Earth's climate cooled, allowing for greater diversity of flora and fauna.
Many of the animals we see today started appearing around this time. Think early horses, camels, canids, eagles, and hawks. In the ocean, marine creatures able to withstand cooler temperatures began to move northwards and southwards, and away from the equator where more animals were able to survive.
The skull was small and researchers say it belonged to a calf. The shorter, wider bones in the front of the fossil differentiate it from other dolphin species in the area and reveal it is not only a new species but a new genus – one that could be an ancient ancestor of the modern-day Platanistoidea (or river dolphin).
In an interview, the study’s lead author Yoshihiro Tanaka explained: "Urkudelphis chawpipacha differs in that it has widely exposed features known as frontals at the vertex in the top of the skull and a strongly pointed feature on one of the ear bones. This bone, termed the periotic, is often unique for a given species."
If you're wondering how it got its unusual name, Urkudelphis chawpipacha is a mashup of four Greek and Kichwa words. Kichwa is one of the 10 native languages found in Ecuador.
"Urku" is Kichwa for "mountain" – a shout-out to the site of discovery (Montañita). "Delphis" is Greek and is often included in the scientific names of dolphins. "Chawpi" and "patcha" are both Kichwa and mean "middle" and "the world respectively". "Middle of the world" is to indicate that it was located near the equator.
As the researchers point out, this discovery could also help improve our understanding of the emergence of the Isthmus of Panama. This is a small area of landmass linking the two continents of America. Its emergence "had a major impact on oceanic and atmospheric currents, and ultimately global climate and diversity," explained Tanaka. The new fossil, he hopes, may provide new insights into when this event took place.