The Museum’s leadership in scientific discovery and research dates back to its founding. To celebrate National Fossil Day, October 13, 2010, the Museum hosted a number of educational activities for school groups: fossil experts used ‘touch carts’ to give students a hands-on look at some of the fossils featured in the Museum’s permanent exhibit halls, and students explored more about how fossils are formed, dated, and collected. Museum scientist Neil Landman’s newly-published research on ammonites will provide even more to discuss.
Although ammonites — shelled mollusks closely related to modern day nautilus and squids — have been extinct for 65 million years, newly published data based on 35 years of research is providing invaluable insights into their paleobiology. Specimens found in the rock record of an ancient seaway that covered North America during the Cretaceous Period reveal fascinating details: ammonites thrived at cold methane seeps that supported diverse ecosystems at the bottom of the sea, consumed small prey, and often survived attacks from predators.
About 70 million years ago, what is now North America was divided in half by a broad inland sea that covered much of the continent. This epicontinental sea, according to the new research published in the Bulletin of the American Museum of Natural History, contained cold methane seeps of bubbling gas that created underwater oases. These ecosystems attracted and supported organisms like bacteria, sponges, gastropods, bivalves, sea urchins, sea lilies, and ammonites.
“You have to imagine the underwater scene 70 million years ago,” says Neil Landman, curator in the Division of Paleontology at the Museum. “A cloud of zooplankton, with ammonites flocking to the vents, forming isolated communities surrounded by the muddy sea floor. Because the sedimentation rates in the seaway were so rapid, the ammonites and other organisms were buried quickly after death, preserving exquisite details of their morphology.”
On Wednesday, September 29, the American Museum of Natural History reopened the famous display featuring the skeletons of two long-time combatants—an Allosaurus and a towering Barosaurus protecting her young—after a separation process that began in early August. The reopening introduced a new feature to this iconic display: an eight-foot-wide pathway that allows visitors to walk between the dinosaurs for the first time.
For nearly two months, the Barosaurus, which soars 100 feet above the floor,and Allosaurus in the Theodore Roosevelt Rotunda had been surrounded by scaffolding while necessary structural work was performed. By cutting a swath through the fiberglass and steel platform which forms the bottom of the mount, the Museum has provided visitors with a fascinating new perspective on these two old favorites.
Known as the greatest dinosaur collector of all time, Barnum Brown helped the Museum establish its world-class fossil collection. In a new book, Barnum Brown: The Man Who Discovered Tyrannosaurus Rex, Museum Research Associate Lowell Dingus and Chair of the Division of PaleontologyMark Norell trace Brown’s extraordinary career from a frontier farm to the world’s top fossil sites to the halls of the American Museum of Natural History. The authors shared some insights in the summer issue ofRotunda magazine.
You write that Brown was “well-built” to become a great dinosaur collector. How so?
Lowell Dingus: Collecting dinosaurs requires a good deal of physical capability in terms of digging, lifting, and carrying large casts. Through his upbringing on the family farm in Kansas, he honed those physical abilities.
Mark Norell: He was well-adapted to harsh conditions in the field, and he was very much a resourceful pragmatist who always found a way to get the job accomplished. He was also well-organized and incredibly loyal to the institution where he worked.
What surprised you most during your research?
Mark Norell: To read his sparse accounts, you would think that his life, with a few exceptions, was fairly mundane. He seemed to downplay almost everything.
How would you sum up Brown’s legacy?
Mark Norell: His legacy is obvious when you walk through our halls and collections, not just for the amount that he collected but also for the skill in collecting it. He also wrote some very insightful papers for his generation.
Lowell Dingus: I was struck when we renovated those halls by how many of the key specimens were his—not just Tyrannosaurus rex, but 56 others. And we still go back to many of the same field areas where he worked to answer the scientific questions raised by the specimens he found. So in those very real ways, his legacy still looms over all of us.
The American Museum of Natural History began the process of separating two long-time combatants — Barosaurus and Allosaurus skeletons — that have shared the same display mount in the Theodore Roosevelt Rotunda since they were first installed in 1991. The separation kicked off with the Museum’s Chair of the Division of PaleontologyMark Norell and visitors overseeing the first ceremonial cut in the mount.
The mounted dinosaurs are the central feature of the Museum’s majestic Theodore Roosevelt Rotunda, which visitors enter from Central Park West, and are a dramatic re-creation of an imagined prehistoric encounter: A Barosaurus rearing up to protect its young from an attacking Allosaurus. The Barosaurus skeleton, which is the tallest freestanding dinosaur mount in the world, is composed of replica bones cast from actual fossils, which would be too heavy to support in this fashion.
By the end of the six-week project, visitors will be able to walk the eight-food-wide pathway between the towering Barosaurus and Allosaurus for the first time.
Fossil preparation requires an uncommon degree of adaptability and patience. (c) AMNH/D. Finnin
Two decades ago, a chunk of sand containing a nearly perfect 80-million-year-old lizard fossil — just pulled loose from the red desert floor and resting on the hood of a Jeep — exploded into dust when touched by a member of the Museum’s annual summer expedition to the Gobi desert. A preparator knows why: paleontology depends on glue.
“Some of the fossils from Ukhaa Tolgod, this massive dinosaur graveyard found in 1993, survive only because they are so tightly packed in sand,” says Amy Davidson, one of the Museum’s senior fossil preparators, who happened to be on that expedition. In a cavernous room perched over several stories of meticulously labeled fossils, she darts to a beautifully fragile and nearly complete dinosaur skull.
“This fossil was also turning into crumbs,” she continues. “We need to know our adhesives. I stabilized the porous bone and sandy matrix (any material in which fossils are embedded) with just the right strength and solubility to be able to sculpt out the fossil, just like a magician pulls a tablecloth from under the table setting.” Last year, this delicate carnivorous cousin toTyrannosaurus rex was described and named Alioramus altai.
Fossil preparation requires an uncommon degree of adaptability and patience. Museum preparators bring to the task diverse sets of skills from such backgrounds as art, paleontology, and archaeology. They generally learn their craft on the job, drawing from related fields such as object conservation to adapt modern glues, solvents, and other archival materials to stabilize fragile areas or repair damage.
But the basic approach remains the same. Davidson, for example, removes her frameless glasses to face a fossil through her microscope, resting her wrists on a black velvet sandbag, securing a fine needle between her thumb and index finger, and using her third and fourth fingers to lightly touch the specimen. She moves almost imperceptibly, for minutes on end, carefully excavating a jaw from the soft sand. At the ready, laid out on a cutting board, are her preferred tools of the trade: brushes and droppers for dispensing glue, needles of different sizes and shapes for excavating, an air pedal for removing scraps of matrix, and glass jars of carefully labeled adhesives. Read more »
Although ammonites — shelled mollusks closely related to modern day nautilus and squids — have been extinct for 65 million years, newly published data based on 35 years of research is providing invaluable insights into their paleobiology. Specimens found in the rock record of an ancient seaway that covered North America during the Cretaceous Period reveal fascinating details: ammonites thrived at cold methane seeps that supported diverse ecosystems at the bottom of the sea, consumed small prey, and often survived attacks from predators.
Known as the greatest dinosaur collector of all time, 
