Carnegie staffers build on the bones of the past
Alan Tabrum's moment of scientific immortality came unexpectedly.
Into the third week of his first fossil expedition for the Carnegie Museum of Natural History in 1994 in China, the paleontologist glanced up through the heat and mugginess enveloping the Shanxi Province's Yuanqu Basin, at what he initially thought was a grasshopper.
On further examination, he saw that it was a fossil jaw with five teeth, which turned out to be the best specimen of a fossil tarsier (a still extant family of primates) ever collected.
Expedition leader Chris Beard, curator and head of the section of vertebrate paleontology at the Carnegie, estimated it was about 40 million years old and, in Tabrum's honor, would later name it Xanthorhysis tabrumi.
The efforts of fossil preparators like Tabrum and his museum colleague Dan Pickering aren't always so publicly dramatic. They often labor patiently, very patiently, and meticulously behind the scenes to, as Beard says, “enable fossils to tell their story” for future generations.
Fossils form the foundation of our understanding of the history of life, says Matthew Lamanna, assistant curator of the section of vertebrate paleontology, but very few of them come ready-made for study. It takes a talented preparator, such as Tabrum and Pickering, to free a fossil from the rock that entombs it, to conserve and stabilize it to the point where it can be handled and studied, or to reassemble a bone from dozens of weathered and broken fragments.
“Good preparators maximize the information available from fossils, adding immeasurably to our knowledge of life on this planet,” Lamanna says.
Playing their roles
Everyone at the Carnegie has a role, says Pickering, 55, who is happy to be an integral part of the ongoing revelation of “what makes our world keep evolving.”
His latest project has him particularly excited, working in conjunction with Lamanna on freeing a fossil from rock that Lamanna brought back from Antarctica. Pickering can't reveal the details yet, but offers this teaser: “It just might be a very significant new species.”
“To be a part of cutting-edge discoveries from the many far reaches of the Earth is extremely exciting and a great honor,” he says.
Lamanna has complete confidence in him.
“I entrust Dan with the preparation of my most important fossils because I know the results will be spectacular,” he says.
Pickering, he says, played a critical role in the construction of the museum's “Dinosaurs in Their Time” exhibit, reconstructing missing or highly distorted parts for many of the mounted skeletons.
Lamanna says Pickering also has become an informal ambassador for the museum's PaleoLab (the publicly visible preparation lab that is a popular stop for visitors) and for fossil preparation in general.
Pickering also was the fabricator of a life-size model of the flattened skeletal remains of an ancient bird called “gansus,” a key link in the earliest stages of bird evolution, that Lamanna and his colleagues discovered in China. It was presented and dramatized in a History Channel series, “Evolve, the History of Flight.”
Beard says that Pickering comes to fossil preparation from a very unusual background, that of an artist and sculptor. That skill set has paid off for the museum in many ways, Beard says.
“He is taking the lead on conserving and reconstructing our historic mastodon skeleton, which needed a face-lift after being on display for over 100 years,” he says.
Pickering says the art world influenced him to look at the natural world of science “and how these beautiful forms have come into being because of the function they perform.”
He was introduced to the museum at about the age of 5 and quickly found it a place that fueled his imagination and curiosity.
“To have a career here working with all the diverse wonders of our natural world is truly satisfying and, in a way, just like home to me,” says Pickering, who has worked at the museum for 16 years.
Keen eye, delicate tough
Alan Tabrum's interest in antiquity and exploration was piqued at a relatively early age, thanks to a set of National Geographic magazines dating to the 1920s that his grandparents owned.
As an undergraduate, Tabrum was chosen to be a field assistant to one of his professors, who had landed a large grant from the National Geographic Society to collect dinosaurs in Baja California.
Lamanna says Tabrum is highly respected by the mammal paleontologists at the Carnegie, renowned for his “eye” for fossils. On more than one occasion, Lamanna says, Tabrum has been able to reunite pieces of the same individual fossil bone that had been collected decades apart.
“Alan is well known internationally for his ability to prepare tiny, delicate fossils that most other preparators would hesitate to touch,” Beard says. “He is a leading expert on North American fossil mammals from the middle part of the Cenozoic Era (25 million to 45 million years ago).”
Tabrum, 66, is proud to have added significantly to the Carnegie's collection of fossil vertebrates from Montana. He says the museum now has the largest and historically most important collection of Cenozoic fossil vertebrates from southwestern Montana.
He currently is heavily involved with 29 million-year-old fossils from Libya, collected in January by Beard and a team of French and Libyan scientists.
He is particularly enamored with the colors, shapes and textures that fossils can exhibit.
“The discovery of a jaw of even the most common mammal in a fauna is always a thrill and provides a nice rush of adrenaline,” he says.
Tabrum says teeth provide the most information, so he tends to concentrate on jaws preserving teeth and on isolated teeth.
The satisfaction in fossil preparation primarily comes for him from doing a particularly good job, especially on a difficult specimen. “Being a preparator is definitely not a job for someone who wants to see instant results,” he says.
He once spent six months preparing an early Eocene primate skull about the size of a quarter. It remains one of his proudest accomplishments.
“I am famous, or infamous, for being a very slow preparator,” he says. “I take pride in what I do and if I try to speed up too much I don't feel like I do a very good job,” he says.
At whatever speed, fossil preparators like Tabrum, Pickering and others, “are always my heroes,” says Zhe-Xi Luo, former curator and associate director of science at the museum, and now a professor at the University of Chicago. “There has always been a lot of hard work by a preparator behind every scientific study on a fossil and behind every spectacular museum display of any original specimen. They are the ultimate professionals.”
“The Carnegie Museum of Natural History would not be able to display original fossil skeletons of dinosaurs and other extinct creatures, if it weren't for the talent and perseverance of our preparators,” Beard says.
Rex Rutkoski is a staff writer for Trib Total Media. He can be reached at 724-226-4664 or firstname.lastname@example.org.