THE appeal of dinosaurs is in the beholding and the imagining. And just when you thought there was nothing new to behold and imagine, along comes the American Museum of Natural History with a provocative exhibition of current research about these wondrous creatures.
The museum's fourth floor, at least a couple of city blocks long, is already filled with the hulking skeletons of tyrannosaurs and other dinosaurs, fierce carnivores and grazing herbivores. Here 5-year-olds, whose fascinations we marvel at as much as the fossils, find themselves entranced and delightfully frightened by the apparitions from the past. The sight of them inspires wide-eyed learning.
Squeezed between the floor's two great halls is a gallery where scientists have now displayed their latest discoveries and interpretations of how dinosaurs walked and ran, attacked and defended themselves, lived and died. You will not learn all the answers to questions a 5-year-old asks, but it's a bold start.
The exhibition, "Dinosaurs: Ancient Fossils, New Discoveries," opens tomorrow and will run through Jan. 8 before beginning a national tour to collaborating institutions.
The show draws heavily on excavations in Liaoning Province of northeastern China, which has emerged in the last decade as one of the world's richest repositories of dinosaur fossils. Embedded in the 130-million-year-old sediments are many previously unknown species, some with clear traces of feathers from head to tail. The specimens appear to support the dinosaurian ancestry of modern birds.Continue reading the main story
The fossils themselves and life-size models of what these dinosaurs looked like occupy the gallery. They are virtually brought to life in a huge diorama of their lush forest habitat long ago in China.
The more dynamic displays include a six-foot-long robotic Tyrannosaurus rex that the museum describes as the most scientifically accurate model ever built of a dinosaur walking.
"We're constantly making new discoveries," Ellen V. Futter, the museum president, said to explain the need for another dinosaur exhibition. "There's so much new study, new understanding and fabulous new exhibition techniques."
Guiding a visitor through the gallery, Dr. Mark A. Norell, curator of the exhibition and the museum's leading dinosaur paleontologist, said, "We're really trying to portray current research work that's being done, not just the gee-whiz of dinosaurs."
Dr. Norell is an outspoken proponent of the evolutionary link between dinosaurs and birds, a theory gaining widespread support among scientists. So it is not surprising that the first fossil specimen encountered here is the well-preserved Bambiraptor, a small predatory dinosaur from Montana. The specimen illustrates the anatomical similarities of certain groups of dinosaurs and today's birds, including a wishbone, swiveling wrists and three forward-pointing toes.
The show's first major section has a more familiar and spectacular look. On the right stands a full-size cast of a T. rex bearing down on visitors below. It is accompanied, just beyond, by a 60-foot-long model of an Apatosaurus skeleton, with silvery geometric arcs replacing the usual assembly of bones.
The two displays illustrate what scientists have learned about the biomechanics of dinosaurs. The construction of the Apatosaurus was based on computer analysis by Dr. Kent Stevens of the University of Oregon. Three large video screens on the wall show animations of the full range of vertebral movements of the long-necked creature.
Across from the huge T. rex cast is the six-foot-long robotic model of the animal. The skeleton moves up, down and sideways in a replication of a striding T. rex out for a fast walk. You can even see the smallest toes flex and curl.
The dynamic model reflects research by Dr. John R. Hutchinson, a computer scientist at the Royal Veterinary College in London who drew on the latest studies of T. rex anatomy and biomechanics. The model was built by Hall Train, a designer of mechanical animations in Toronto. "Making the robotic T. rex," he said in a museum statement, "was the most challenging project in my life, because it required coaxing machine parts to convey movements that are organic and fluid."
In the same section, visitors can conduct their own experiments in dinosaur locomotion. At interactive stations, they can enter changes in an animal's leg muscle mass, posture and center of gravity and observe how this affects the speed and gait of a walking or running T. rex. Comparisons are shown with the locomotion of crocodiles, elephants, horses and humans.
Moving to the second section, on dinosaur behavior, you see the re-creation of tracks left by a dinosaur herd in Texas. Recent studies of the prints have given scientists new insights into dinosaur herding behavior: how many in a herd and how the big animals moved in front and along the sides, with smaller ones in the middle for protection from predators. It reminded scientists of the ways of elephant herds.
The section also has a "trophy wall" of mounted dinosaur skulls, some with horns, spikes, crests and domes. Scientists offer various explanations as to their purpose, whether they were used for defense, mate recognition or display. "Fact is," Dr. Norell said, "we don't really know which of these three hypotheses is going on."
The exhibition centerpiece comes next: the diorama of the Liaoning forest in China. The trees are pine and cedar, which shade a ground floor of ferns. Actually, the setting is based on plant specimens from the New Jersey Pine Barrens, which paleobotanists suggested as closely approximating the Liaoning ecosystem when dinosaurs dwelled there.
Look closely and you will see the life-like models of its inhabitants, all based on recent discoveries. One is a primitive tyrannosaur covered in a featherlike coat. Gliding between the trees is a creature that looks like a dragonfly on home run-grade steroids. The Microraptor is three feet long with feathers and two sets of wings, one on its arms and the other on its legs.
On the ground, a small birdlike dinosaur, Mei long, is sleeping or resting in birdlike repose. Its head is tucked between its forearm and trunk and its tail encircles its body. This is almost identical to the way modern birds sleep with their heads under a wing. Chinese and American paleontologists say this is further evidence that birds evolved from dinosaurs and that some dinosaurs were warmblooded.
In another part of the forest, a parrot-beaked dinosaur, a psittacosaur, is trailed by her babies, like a duck and her ducklings. Not far off, there is a dog-size animal named Repenomamus giganticus, the largest mammal yet found from the time of dinosaurs. Its presence is ominous. A related mammal was recently discovered and in the area of its stomach was its last meal: a juvenile psittacosaur. This is the first evidence that not all mammals then were entirely subservient to the reptilian lords of the land, at least not the smallest ones.
Although the diorama animals are models, the exhibition shows a number of the actual fossil specimens from which the models were reconstructed. At nearly every turn, there are interactive stations for calling up more information on each exhibit and videos showing scientists talking about their research and what it adds to our understanding of dinosaurs.
The final section is, appropriately, on the dinosaur extinction 65 million years ago. Much is made, of course, of the asteroid or comet that struck Earth at that time and contributed to a mass extinction of life. But other things were going on, including global climate change and widespread volcanic eruptions, and so the show's scientists have left us without a conclusive explanation for the dinosaurs' doom. Why, for example, did birds survive and not other flying or gliding creatures, like pterosaurs? Why did all nonavian dinosaurs large and small die out, and not other reptiles like crocodiles and turtles?
Nothing about dinosaurs, it seems, is simple or entirely resolved, and this justifies the new exhibition at the natural history museum and makes the creatures all the more fascinating to behold and imagine.
"Dinosaurs: Ancient Fossils, New Discoveries" opens tomorrow at the American Museum of Natural History, Central Park West at 79th Street, (212)769-5100, and will run through Jan. 8. It travels to the Houston Museum of Natural Science (March 10 to July 30, 2006), the California Academy of Sciences, San Francisco (Sept. 15, 2006, to Feb. 4, 2007), the Field Museum, Chicago (March 30 to Sept. 3, 2007) and the North Carolina Museum of Natural Sciences, Raleigh (Oct. 26, 2007 to July 5, 2008).Continue reading the main story