Nick Pyenson Reconstructs Bygone Whale Populations Using Fossils

The Smithsonian National Museum of Natural History paleobiologist also studies the evolution of echolocation and special sensory structures in modern whales.

Jul 1, 2018
Jim Daley

Nick Pyenson first fell in love with natural history museums as a child, growing up in Montreal when his parents would take him to McGill University’s Redpath Museum and Harvard’s Museum of Comparative Zoology to learn about the diversity of Earth’s animals, plants, and ecosystems. Seeing the skeletons of large animals, especially those of whales, got him thinking about the stories marine mammals had to tell. In 1998, Pyenson went to Emory University and while he was there started studying whale brains. During a college trip, he and his friends “found a dead dolphin on a beach,” he recalls, “and I thought it was totally fascinating.” The dolphin led Pyenson to question how well the fossil record represents past life. “Understanding pathways of decay and destruction,” he says, “is . . . a big part of what paleobiologists do.”

In 2003, Pyenson, now a paleobiologist and curator of fossil marine mammals at the Smithsonian’s National Museum of Natural History in Washington, D.C., headed to the University of California, Berkeley, where he started his graduate work studying the evolution of whales. Stanford zoologist Jeremy Goldbogen, then a master’s student at the Scripps Institution of Oceanography, remembers a conversation the two had about how large whales feed. “Nick . . . brings a lot of knowledge about how living whales work to understand what life was like in the [ancient] oceans,” Goldbogen says.

Pyenson decided to investigate how ancestors of toothed whales, such as dolphins and sperm whales, came to use echolocation. With his Berkeley advisor, David Lindberg, Pyenson published a study in 2007 suggesting that whales developed the trait to hunt cephalopods at night in the shallowest level of the ocean, and later adapted it for diving down to hunt them at greater ocean depths.1 Pyenson also met Susan Kidwell, a paleobiologist at the University of Chicago, at the time. She’d been comparing distributions of live and dead mollusks to determine how well the fossil record represents animals that lived in the past. “Nick . . . very cleverly thought to try to do the same kind of comparison focused on whales and other marine mammals,” she says. But recently deceased whales are harder to find than dead mollusks. So Pyenson reviewed literature and agency records on whale strandings and found that they closely reflect the patterns of richness and relative abundance of modern-day whales along coastlines, suggesting that the fossil record similarly reflects the diversity and relative abundance of whales in the past.2

That same year, Pyenson started working with Goldbogen on feeding in baleen whales. These behemoths, such as blue whales and fin whales, use a feeding pouch with specialized blubber that’s very stretchy—and lined with muscle and nerves—to take giant gulps of seawater and krill, filter out the water, and swallow the rest, says Goldbogen. Embedded in the pouch is a unique mechanosensory organ that coordinates the movement of different muscles involved in filter feeding, Goldbogen and Pyenson reported in 2012.3

In June, Pyenson published Spying on Whales: The Past, Present, and Future of Earth’s Most Awesome Creatures, which describes how whales evolved from relatively small land-based creatures to the largest organisms that ever lived on Earth. Science, Pyenson says, is all about “telling stories, telling true narratives about the world.” It takes creativity, he says, along with a bit of detective work.  

References

  1. D.R. Lindberg, N.D. Pyenson, “Things that go bump in the night: evolutionary interactions between cephalopods and cetaceans in the tertiary,” Lethaia, 40:335–43, 2007. (Cited 42 times)
  2. N.D. Pyenson, “The high fidelity of the cetacean stranding record: insights into measuring diversity by integrating taphonomy and macroecology,” Proc Royal Soc B, 278:3608–16, 2011. (Cited 65 times)
  3. N.D. Pyenson et al., “Discovery of a sensory organ that coordinates lunge feeding in rorqual whales,” Nature, 485:498–501, 2012. (Cited 55 times)