Ancient Whale Named for UW Paleontologist Elizabeth Nesbitt
A newly discovered species of whale — found preserved in ancient rock on the Oregon coast — has been named for a University of Washington paleontologist.
“It’s a tremendous honor,” said Elizabeth Nesbitt, who is curator of invertebrate paleontology and micropaleontology at the Burke Museum and an associate professor in the UW’s Department of Earth and Space Sciences.
Maiabalaena nesbittae lived about 33 million years ago and was described in a study published in Current Biology by researchers at the Smithsonian’s National Museum of Natural History in Washington, D.C.
The genus portion of the name combines “balaena,” the Latin word for whale, and “maia” meaning mother, because this species, that had neither teeth nor baleen, is the intermediate stage between modern, filter-feeding baleen whales and their toothed whale ancestors. The Smithsonian paleontologists concluded that this whale used suction to pull fish or squid into its mouth.
While Nesbitt’s research is mostly on smaller fossils of marine animals without backbones, she was instrumental in figuring out the age of Washington and Oregon rocks that the marine mammal fossils are found in. In January 2018, Nesbitt published a paper about the ages of the geologic units in Washington and Oregon that are younger than 50 million years old.
“I use the fossils, mostly different types of clams and snails, to tell geologic time,” Nesbitt said. “Any one species, or any group of species of fossil, lives for a certain period of time. Then when they die, they’re gone. You’re never going to see those guys again, thus each group characterizes a geologic time span,” Nesbitt said.
She compares the fossil assemblages from the Pacific Northwest with those in other parts of the world to pin down dates. Dating rocks is especially tricky in the Pacific Northwest, she said, which is isolated from other land masses and geologically complex.
“If you go to the Gulf Coast, everything’s in nice layers. Here, because of plate tectonics, because of the Olympics and the Cascades, everything is tilted, folded and out of sequence. And the other problem in the western Pacific Northwest is dense vegetation covering the rock outcrops. So the dating is much more complicated here than other places in the world,” Nesbitt said.
Another challenge in the dating for the new species, she added, was the rock samples attached to the fossil were just small slivers.
The fossil of the M. nesbittae had been collected in Oregon in the 1970s and sent to the Smithsonian. It wasn’t until lead author Carlos Mauricio Peredo, a doctoral student at George Mason University and predoctoral fellow at the Smithsonian, was investigating very early marine mammals that he realized this specimen’s potential evolutionary importance, Nesbitt said.
The M. nesbittae was likely the size of a dolphin. Researchers do not know how widely it roamed. It just happens that the Pacific Northwest is one of the best places in the world — along with Japan and New Zealand — to find fossils of whales.
“First of all, we have the rocks of the right age, from around the 30-million-year-old time period in which there was an absolute explosion of whales of different types,” Nesbitt said.
“Secondly, when these sediments were deposited the water was deep. So the deeper the water the better chance you have of preserving the fossils — when these rocks were collected they’re essentially sitting in concrete. It takes an incredible amount of time to prepare them.”
Over the course of her career, Nesbitt has explored almost every part of the coast in Washington and Oregon. At this point in her career, she does less fieldwork, since many of the fossils are found on steep cliff faces. But she recently collected whale fossils on Vancouver Island with Nicholas Pyenson, an affiliate curator at the Burke Museum and a co-author on the Current Biology paper.
Nesbitt is also involved in an ongoing project with the Washington Department of Ecology studying modern-day marine microorganisms, from the mid-1990s to today, to learn about changes in Puget Sound ecology.
Nesbitt encourages people in the Seattle area to explore the fossil whales on display at the Burke Museum, many of which were collected by Burke research associate James Goedert and prepared by staff member Bruce Crowley.
As for the new whale, the authors write that “the specific epithet nesbittae honors Dr. Elizabeth Nesbitt, for her lifetime of contribution to the paleontology of the Pacific Northwest and her mentorship and collegiality at the Burke Museum of Natural History and Culture.”
Source: www.washington.edu