Shell shock: Collectors help the Museum crack the case of a missing specimen

Forty-seven years ago, celebrated shell collector Jack Lightbourn hauled a new species up with his large catch of mollusks off the coast of Bermuda. The prime sample of the species, later named C. lightbourni, was sent to the Delaware Museum of Natural History in the mid-1970s and studied by a graduate student several years later – before mysteriously disappearing from the collection.

Rumors flew as researchers and shell enthusiasts speculated for decades about the shell’s whereabouts. Most concluded that the specimen fell into the wrong hands of a private collector, hidden from the public access otherwise afforded in an academic setting. And then Bill Fenzan arrived at the Museum with the shell in his pocket.

“I could not believe Bill had found this long-lost specimen, which has tremendous scientific value for the Museum’s collections,” said Curator of Mollusks Liz Shea, Ph.D. “This is an extremely rare shell only found in Bermuda, and I wasn’t sure that we’d ever recover this specimen or unravel what happened.”

The shell’s long and winding journey to the Museum’s permanent collection started in the early 1970s when Lightbourn and Arthur T. Guest developed an effective new way to collect gastropod shells: by trapping the hermit crabs who lived inside the shells with baited lobster traps. The specimens harvested in Bermuda by the two conchologists were well known in mollusk circles, and many new species were discovered based on the findings. Lightbourn sent many specimens to his colleagues at the Delaware Museum of Natural History.

A University of Miami graduate student, Ed Petuch, regularly visited the Museum’s collection at that time and wrote the original description of C. lightbourni, which was eventually published after considerable delay in the Proceedings of the Biological Society of Washington in 1986.

In the meantime, the shell vanished. Over the years, Museum curators tried to piece together the location of the missing shell without success. They wrote letters to Ed Petuch, queried an online listserv, and asked researchers and shell collectors for help, but nothing was ever resolved.

Unfortunately, there was no paperwork associated with the specimen – no donation papers, thank you letters, or loan documents. Once designated as the holotype, or the best example of a newly discovered species, the specimen should have been obviously marked and its movements accompanied by paperwork. In this case, that did not happen.

Ed Petuch suggested that the shell may have travelled to Bermuda for further study because there was a lot of interaction between the Museum and Bermuda in the 1970s and 1980s.

“It seems that the shell made a trip back to Bermuda,” said the Museum’s Liz Shea, Ph.D. “And it’s still not clear exactly how it got lost in the shuffle.”

In 2008 the shell was located in the same way so many great discoveries are made: by accident. A known collector of the Conus genus, Bill Fenzan, received a phone call out of the blue from a San Diego shell dealer who had recently purchased Jack Lightbourn’s prized personal collection. The dealer found that the collection contained not just one specimen of C. lightbourni, but two – the second uncovered in a container labeled “Bermuda miscellany.” The dealer sold one of the specimens for a few thousand dollars to Bill, who quickly ascertained that it was indeed the missing holotype.

The story of its discovery was the highlight of Mid-Atlantic Malacologists Meeting in 2008. DMNH 134938 is now happily housed in the mollusk collection at the Museum. “Researchers can come visit, measure, photograph, and otherwise study this beautiful shell,” Liz said. “Just don’t ask to borrow it.”

What’s your type?

When scientists discover a new species, they collect several examples of the animal. This group of examples is called a “type,” and it is used to show other scientists what the species looks like and what slight variations there may be within the species. One example from the type is selected as the “holotype,” or the prime example of this new species. The other examples within the type are called “paratypes.” The Delaware Museum of Natural History is privileged to house several hundred types among its collection of approximately 2 million shells.

This article first appeared in the Winter 2008-09 issue of Discovery magazine.