Two Smithsonian scientists reexamined the while fossils of a 15-million-year-old sperm whale sitting on a museum storage shelf and their findings couldn't be more surprising: the fossils are of an undiscovered sperm whale species, not extinct walruses as previously thought.
Welcome the Albicetus oxymycterus, which the scientists at the Smithsonian's National Museum of Natural History discovered after reexamining the fossil originally described in 1925. Back then 90 years ago, a scientist known as Remington Kellogg called it Ontocetus oxymycterus, miscategorizing it as a member of an extinct walrus group.
The study dubbed the new genus "white whale," owing to the bone-white color of the fossils and paying homage to the mystical leviathan in Herman Melville's novel "Moby Dick."
Nick Pyenson, marine mammal curator in the museum's paleobiology department, said the fossil maintains an ashen white color, although the real-life skin color is still unknown.
"It only seemed appropriate to evoke Melville's white sperm whale, Moby Dick," said Pyenson in a press release, particularly as they studied A. oxymycterus in contrast with the skeletons of some of its modern-day kin in the Smithsonian collections.
The researchers also compared the jaw bones and other parts with those from 36 other sperm whale samples, both extinct and existing. Pyenson highlighted the fossil's sheer size, particularly the block preserving the jaws and skull likely weighing a few hundred pounds and needing plenty of muscle for mobility.
"It's only with recent advancements in 3-D digitization that we were able to capture the entire geometry of this specimen," he added.
Lead author Alexandra Boersma said that the findings also offered an insight into the role of the fossil creature into the sperm whale's evolution. Modern sperm whales are considered unique in that they can dive almost two kilometers, have complex social networks, and own the largest brain among living creatures today, she explained.
Understanding the living sperm whale's history and evolution has plenty of implications even for studies outside of paleobiology, she added.
Boersma and Pyenson, who also created a 3D model of the Albicetus specimen, estimated that the new species grew to about 20 feet long, meaning it is moderately sized among sperm whales, with the modern species possibly exceeding 60 feet in length.
Big teeth found in fossil sperm whales, too, suggested they fed on huge prey, including smaller whales and seals. In contrast, modern ones largely lacked upper teeth consumed on squid primarily.
The findings were published Dec. 9 in the journal PLOS One.
Photo: Biodiversity Heritage Library | Flickr
