A single nearly complete skull of a mysterious fossil dolphin (Figure 1) was collected by the late fossil-finder extraordinaire Doug Emlong (1942–1980) in March of 1969 from coastal Oregon (Lincoln County), south of the Yaquina River. Remarkably, this skull remained unstudied for nearly 50 years until a team of fossil dolphin enthusiasts from Belgium, the United States, and Australia “rediscovered” it in the vast collections of the National Museum of Natural History (The Smithsonian Institution). Fortunately, this beautiful skull representing a new family, genus, and species of extinct dolphin has now been brought to light. Consequently, our knowledge of the remarkable diversity of extinct dolphins continues to increase. This new archaic dolphin named Yaquinacetus meadi is approximately 22 million years old, and lived long before modern dolphins or porpoises appeared in the oceans.
Although not closely related, the skull of the ancient Yaquinacetus is similar in size and shape to that of the living spinner dolphin (Stenella longirostris). In life, Yaquinacetus would have been about 8’ long (Figure 2). Its skull was equipped with approximately 160 pointed teeth – useful for hunting slippery fish or squid. Yaquinacetus is represented by only a single specimen. Imagine, of all the millions or billions of individuals of this kind of dolphin that ever existed, this one Smithsonian specimen is the only one of its kind known to science. We don’t know how far and wide its habitat ranged, nor how long it lived on Earth, or if it had any descendants; but we know that it existed.
What we can say for sure is that the skull of Yaquinacetus is sufficiently different from other known archaic dolphins that together with one other extinct dolphin, Squaloziphius emlongi (also known from only a single specimen collected by and named in honor of Doug Emlong) from the early Miocene epoch of Washington State, they comprise a new family of toothed whales, the Squaloziphiidae. It is very exciting that a completely new family of dolphins has been named based on these exceedingly rare fossils. We expect that there are other fossil squaloziphiid dolphins out there or hiding in museum collections just waiting to be found. These discoveries confirm the northeastern Pacific as a center of diversification for several groups of archaic dolphins during the late Oligocene – early Miocene (i.e. 25 – 20 million years ago).
This publication is the result of collaboration between the Royal Belgian Institute of Natural Sciences (Brussels, Belgium), the Calvert Marine Museum (Solomons, Maryland, U.S.A), Museums Victoria (Melbourne, Australia), and the National Museum of Natural History, Smithsonian Institution (Washington, D.C., U.S.A.).
How the new dolphin got its name: Yaquinacetus, a combination of Yaquina, for the Yaquina River (and the Native American tribe formerly living in that region), that flows into the Pacific Ocean a few kilometers north of the locality where the skull was discovered, and cetus, whale in Latin. In addition, meadi (the name of the new species) honors Dr. James G. Mead (Figure 3, Curator Emeritus of marine mammals in the Division of Mammals at the Smithsonian Institution) for his life-long work studying and describing the anatomy and ecology of whales and dolphins.
The new dolphin’s family name is “Squaloziphiidae”, because some of their cranial features are reminiscent to those in modern beaked whales (family Ziphiidae). This makes the dedication of the new species to Dr. Mead even more relevant. Indeed, Dr. Mead’s principle research interest is beaked whales, on which he has published numerous scientific works, including contributions to the description
of several new living species (an outstanding achievement for a specialist of such large marine mammals).
The paper, just published in the Journal of Vertebrate Paleontology, is entitled:
YAQUINACETUS MEADI, A NEW LATEST OLIGOCENE-EARLY MIOCENE DOLPHIN (CETACEA, ODONTOCETI, SQUALOZIPHIIDAE N. RANK) FROM THE NYE MUDSTONE (OREGON, U.S.A.) by Oliver Lambert, Stephen J. Godfrey, and Erich M. G. Fitzgerald