Meet Wimahl chinookensis, a new species of fossil dolphin that lived about 18 million years ago in the waters of the Pacific Northwest. The ancient dolphin is an early relative of modern dolphins and porpoises.
The fossil dolphin was found along the north bank of the Columbia River and its name “Wimahl” is the name for the Columbia River used by local Chinook peoples, translating to big river.
This holotype specimen—the single physical example of a species—is part of the Burke Museum’s vertebrate paleontology collection. Visiting researcher Carlos Mauricio Peredo and colleagues from George Mason University in Virginia recently published their research, including naming the new species, in the Journal of Vertebrate Paleontology.
“When I first saw the fossil, I was amazed at how complete it was,” said Carlos. “The specimen includes not just a complete skull, but a complete vertebral column and parts of both flippers.”
“We are very fortunate to have such complete fossil; it provides a baseline for comparing other fossil dolphins,” said Carlos.
Traditionally, fossil dolphins from this time period have been called kentriodontids. However, many are known from only a handful of bones, making it difficult to properly compare one fossil species to another.
“Because Wimahl is such a complete specimen, it proved extremely useful in resolving the relationships amongst kentriodontids,” said Carlos. “This, in turn, helps us understand the origin of modern dolphins.”
The fossil dolphin is being 3D scanned to create a cast that will be on display in the new Burke Museum opening in fall 2019, with the holotype remaining available for study in the research collection.
Special thanks to Carlos Peredo for his contribution to this story.