PUTTING DINOSAURS TOGETHER
What happens to excavated dinosaur bones after they reach a museum?
What happens to excavated dinosaur bones depends on whether or not the museum or institute plans to exhibit the find in the near future. If there are no immediate plans for the bones, they will be placed in safe storage until time and funds are available for their preparation. However, if the skeleton is to be put on display relatively quickly as in the case of a new, spectacular species then the bones will go through a fairly standard preparation process.
Simply put, the bones must be removed from the encasing rock during the preparation process. Next, any missing parts must be identified and a substitute found. Lastly, the bones are attached together and the entire skeleton is mounted for display. This process is tedious and time-consuming. For example, it took seven years of work until the Apatosaurus at the American Museum of Natural History in New York City was exhibited to the public.
How are dinosaur bones prepared for study and display?
The process of preparing dinosaur bones excavated from the field is generally done in a laboratory, where a wide variety of tools and chemicals are available. The first step in preparation is to remove the rock from around the bones, using hand tools, dental picks, needles, microscopes, small pneumatic tools or anything else that does the job. This technique is laborious and exacting, and can only be mastered through hours of hands-on experience. Once the bones are exposed, they must be repaired, if needed, and stabilized to prevent further degradation. There are a wide variety of glues and adhesives that serve this purpose. Weak or cracked bones may require the addition of structural supports, such as fiberglass or steel bands.
How are missing dinosaur bones restored to a skeleton?
When a dinosaur skeleton that is to be exhibited has missing bones (which is the case for the vast majority of fossil finds), these bones must be restored. This is accomplished in a variety of ways: Some missing bones can be replaced with fossil bones or casts from another individual of the same dinosaur species. Often times, two or more partial skeletons can be combined to produce one complete skeleton. If these methods can not be used, the missing bones can be sculpted from a variety of materials, such as wood, epoxy, or ceramic.
Mounting a dinosaur fossil for display is almost more art than science. Often missing bones need to be replaced with molds, and sometimes new discoveries make it necessary to rearrange the bones already mounted (Big Stock Photo).
How are dinosaur bones mounted for display?
Once the fossilized dinosaur bones have been prepared and stabilized and any missing pieces obtained the skeleton is ready to be free-mounted. The purpose of the mounted dinosaur is to display the skeleton as it might have looked in real life.
The first step, as in any large-scale project, is planning. Sketches and scale models are made, showing what the display will look like. Any variations to the posture perhaps to reflect new information or to make the display more realistic can be made at this stage, avoiding costly changes during actual assembly. The sketches and models will also show whether the skeleton will fit into its designated exhibition space. It would be very costly, time-consuming (not to mention embarrassing) to find out during assembly that the skeleton does not fit. A good, final sketch can also be used as a guide during the actual assembly, as well as showing where extra support is needed.
Next, a strong steel armature (or armatures) is constructed and the individual dinosaur bones attached to it, in their proper places, of course. The armature is custom-made to provide enough support, but shaped to be unobtrusive.
Because dinosaur bones are brittle, no stress can be placed on them; the armature is designed to support the weight of all the bones. Attachment of the bones to the armature is made using pins, bolts, or steel straps. Sometimes, it becomes necessary to hang cables from above to provide more support for parts of the skeleton.
Once the entire skeleton is mounted, there are still a few more details: the base on which the skeleton rests must be made visually appealing; barriers must be placed around the mount to protect it from the curious; and labels and display information created and positioned. At last, the dinosaur skeleton, which has remained hidden for millions of year, is ready to be viewed by the public.
Do dinosaur bones ever get rearranged after they are mounted?
Yes, dinosaur bones have been rearranged after they were mounted. This is because the field of dinosaur study is constantly changing as more bones are found, or more studies are completed. For example, in early 1999, scientists used a computer model of sauropod dinosaurs dinosaurs with a neck up to 40 feet (12 meters) in length. Most of these animals were posed by museums with long S-shaped necks that would allow them to reach high into the tall trees to gather leaves. But the computer model indicated that the animals could not lift their heavy necks because the vertebrae were too heavy. These dinosaurs probably kept their necks straight out and may have chewed on lower-lying shrubs. Thus, many museums had to rearrange their sauropod mounts to fit the newest discovery.
How will modern technology help paleontologists prepare, reproduce, and study dinosaur fossils finds in the near future?
New technologies are rapidly changing the way paleontologists prepare, reproduce, and study dinosaur fossils. For example, Computed Tomography (CT) uses X-rays to generate a three-dimensional image of an internal structure of an object; it has already been used to determine if fossilized eggs contain baby dinosaur remains. Only those rocks containing fossils, or those eggs that contain baby dinosaurs, will be prepared, eliminating much of the destructive guess-work. In the near future, lab workers will also have available a three-dimensional image of a specimen to help them in the preparation process.
Once fossil remains have been prepared, precise measurements will be made using new instruments such as electronic calipers, or two- and three-dimensional digitizers. This data will be sent directly to a computer, which will guide machinery to automatically generate reproductions of the remains in materials such as metal or plastic. This process will make highly accurate casts available to more scientists (and the public) at lower costs. Another exciting possibility is that three-dimensional data might be obtained from such non-destructive techniques as CT, allowing paleontologists to make highly accurate reproductions of dinosaur fossils without ever removing the fragile bones from the encasing rock.
The research into dinosaur behavior and physiology will be greatly enhanced by the combined use of three-dimensional imaging, modeling, and virtual reality. Scientists will be able to study individual specimens, or even complete skeletons, from any angle or view, including from the inside looking out. And with data stored on computers, paleontologists will have much quicker access to rare specimens data. Such systems as the World Wide Web now allow scientists to study a rare specimen on the computer without having to travel to the few museums and institutions that house the actual fossils. Interestingly enough, even our computer games have been affected by such computer advances, with dinosaur games showing more realistic versions of these creatures.