March 9, 2012
This post is part of our on-going series in which ATM invites guest bloggers from among the Smithsonian Institution’s scientists, curators, researchers and historians. Today, Nick Pyenson, curator of fossil marine mammals at the National Museum of Natural History makes his debut and tells the story of an inadvertent discovery while working with the collections.
Any job has its tedious work. Personally, I loathe filing receipts and other bureaucratic paperwork. But one of the more enjoyable aspects of my job is the privilege of plying through drawer after drawer of the huge floor-to-ceiling storage cabinets that house the nation’s paleontological collections.
When I first arrived at the Smithsonian nearly three years ago, one of my first tasks was to familiarize myself with the museum’s fossil marine mammal holdings. Every day as the new curator of the collections, I make decisions about the care and status of not just our most important specimens, but also minor pieces that have over time been forgotten, misidentified or even misplaced—curatorial problematica, in our parlance. The roots of the collection date to the museum’s earliest days at the start of the 19th century (which is a story for another time), while the bulk of the specimens represent named species that were described in the early- to mid-20th-century.
So there are always surprises. And, as any researcher who uses museum collections can tell you, there is a certain thrill that comes when opening drawer after dusty drawer to discover the treasures within.
About a year ago, graduate student Jorge Velez-Juarbe and I came across a fossil dolphin skull that had long been identified with a hand-written label as “Delphinapterus sp.” To the initiated, the label meant that the specimen was informally assigned to the living genus of beluga (the full species name is Delphinapterus leucas). And given its coordinates in time (the Pliocene Epoch) and location (Virginia), it wasn’t too surprising of an identification, as several bits and pieces of distinctive remains that were clearly from beluga have been known from the same region for many years.
In fact, I had seen a cast made from the same specimen in the collections at the University of California Museum of Paleontology, in Berkeley, and I was dimly aware that it might have been of some interest well before my time. The cast at Berkeley comes from a mold of the skull made several decades ago, under the aegis of Frank C. Whitmore, Jr., now retired from the U.S. Geological Survey, and a longtime mentor to many generations of students studying fossil marine mammals at the Smithsonian. (Frank is also the only surviving founding member of the Society of Vertebrate Paleontology). Because many specimens are entirely unique—especially in paleontology, where a single specimen may be the only known representation of a vanished lineage—researchers will request and trade replicas, which give us the opportunity for side-by-side comparisons that provides a complete beastiary of osteological traits to survey. Paleontologists often wear many intellectual hats, and one of them is that of a comparative anatomist. After many years of training, you gain the ability to discern the identity of an animal from its scraps.
Back to the skull in question. Jorge and I realized that a side-by-side comparison with an actual beluga or narwhal skull would reconfirm its identity. In this case, we could tell that the skull shared a close kinship with belugas and narwhals (which, together are most closely related to one another among all other whales). Though decidedly low-tech, paleontologists have hand-carried and transported specimens for visual inspections for more than 200 years—the gold standard for describing new species. One of the advantages of being at the Smithsonian is having access to the world’s pre-eminent modern marine mammal skeletal collections, and so Jorge and I packed the skull in its secure storage cradle and took it by shuttle to the Museum Support Center (MSC), the museum’s off-site extra storage facility, in Suitland, Maryland.
On the MSC campus, large, secure warehouses store the unwieldy skulls and bones of blue whales, sperm whales and right whales, all in in archival conditions. There, after comparing the fossil skull with many individual adult, juvenile, male and female beluga and narwhal skulls—an exercise that also provided a sense of basic biological variation in traits—we realized that the fossil skull was neither beluga nor narwhal. Nor was it like any other described fossil species.
What we had, we finally concluded, was a new genus and species in the whale family Monodontidae (the taxonomic category belonging to belugas and narwhals, and any extinct relative between them). We used the opportunity to name the skull after a colleague at the museum, David Bohaska, to honor Dave’s life-long dedication to caring for fossil marine mammals.
The discovery of Bohaskaia connects to so many aspects of the work that scientists do, especially those who have devoted their careers to studying marine mammals both modern and fossil. But the story is also one that has been repeated many times elsewhere throughout the National Museum of Natural History, a place with such a robust legacy, and so crammed full of the world’s most historic collections—127.3 million by last count—that scientific discovery delivered through routine analysis and comparative study is just a work-a-day experience. And that’s a job worth doing, especially when it crosses generations.
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