It's easy to to be impressed when you walk the halls of museums by the quality and quantity of specimens on display, but it is only a fraction of what institutions like the Academy of Natural Sciences of Drexel University and other comparable institutions have in their collections. This year, the Academy celebrates its 200th anniversary and to mark the occasion, has created a year-long exhibit titled The Academy at 200: The Nature of Discovery. The exhibit pulls out scores of hidden gems that have been taking up shelf space in the collections, that is, until now.
For these specimens to be prepared for display takes an enormous amount of work. There's the making of display cases and mounts. The lighting and signage must be crafted. The specimens must be in good enough condition to survive the hot lights, heavy traffic, and potential damage being on display could introduce. And sometimes, they need to be spruced up a bit before going on display.
Fred Mullison, the fossil preparator in the Academy's Vertebrate Zoology department (and the mentor who trained me to run Neil Shubin's lab), is one such sprucer-upper. When it was decided that the extinct Irish elk the Academy had was to be prepared for display in The Academy at 200 exhibit, they quickly realized no self-respecting elk would appear in public without a full set of teeth. So if you've ever found yourself asking, "If I knew a toothless elk, what would I get it for its birthday?" ask no more. The answer is a set of dentures. (Aw, shucks! Really? You shouldn't have!)
Shockingly, there are not many people trained in the fine art of making dentures for extinct elk. Luckily for our friend the elk, people like Fred Mullison are armed with a unique set of skills that includes a deep understanding of anatomy, an artistic eye for sculpting and modeling and the technical knowledge of the ways of molding and casting. Not to worry, you vain little elk. Fred's gotchya covered; undoubtedly you will look smashing for the exhibit's roll-out.
Shall we take a behind-the-scenes tour through the process? Fred was kind enough to provide me with extensive photographs and descriptions of his work. What follows is a photo essay based off a series of emails we exchanged the week of the exhibit's opening. Enjoy!
This is the Academy’s darling fossil Irish elk. Looks pretty good for being 10,000-25,000 years old! (Photo by Fred Mullison, Academy of Natural Sciences)
Here you can see a closeup of the Irish elk’s maxilla before Fred got his hands on it. As you can see, his teeth are in rough shape. (Photo by Fred Mullison, Academy of Natural Sciences)
Mammal teeth are diagnostic, meaning you can pick up a mammal tooth from virtually any time period and hand it to an expert to ID with little other information. The Irish elk was originally determined to be an elk because of its teeth’s similarity to the modern elk, Cervus canadensis. As such, Fred felt confident using this modern elk skull as a basis for the reconstruction. (Photo by Fred Mullison, Academy of Natural Sciences)
If you’ve ever had a tooth pulled, you know how far your teeth’s roots extend into your jaw. Well, Irish elk are no exception, and to begin sculpting the dentures, Fred needed to construct a solid base for the dentures which would fit neatly into the fossil skull. He did so by filling the hollow tooth wells with Super Sculpey clay and creating a flat pedestal (background) on which he would build the actual teeth (foreground). (Photo by Fred Mullison, Academy of Natural Sciences)
Then, using his extant Cervus Canadensis teeth as a model, Fred used Super Sculpey clay to sculpt the actual teeth. (Photo by Ned Gilmore, Academy of Natural Sciences)
The same process is used for the teeth in the mandible. (Photo by Ned Gilmore, Academy of Natural Sciences)
After the Super Sculpey clay is hardened in an oven, Fred refines the teeth using a small Dremel tool. (Photo by Ned Gilmore, Academy of Natural Sciences)
Adding the finishing touches to the elk teeth. (Photo by Ned Gilmore, Academy of Natural Sciences)
The elk’s teeth are ready to cast. (Photo by Fred Mullison, Academy of Natural Sciences)
Silicone rubber molds (blue material) are made from the Super Sculpey models. Then the original models are removed from the molds and the polyester resin can be poured in to make the permanent dentures. Polyester resin, of the type used in boat and automobile repairs, is relatively easy to work with and very durable. It is lightweight, can be painted with any type of paint, and can be drilled, sanded, and glued, making it ideal for fossil replicas and reconstructions. (Photo by Fred Mullison, Academy of Natural Sciences)
The polyester dentures are checked for proper fit and can then be painted. For the base coat, Fred used a black spray acrylic enamel of the sort used in painting plastic hobby models. This creates a shadow effect in the recesses of the fossil teeth that give it an authentic look and help it match the real fossil. (Photo by Ned Gilmore, Academy of Natural Sciences)
The teeth are painted and the skull is ready for mounting. From start to finish, the whole process took 6 weeks of solid work. (Photo by Fred Mullison, Academy of Natural Sciences)
The Academy at 200: The Nature of Discovery will be on display through March 2013 as part of the Academy of Natural Sciences of Drexel University's bicentennial celebration. In addition to the regular exhibit, each month the Academy is highlighting a different department by offering behind-the-scenes tours of the collections. April is highlighting the Mineralogy collection; May will focus on the Ewell Sale Stewart Library and Archives; June will be for Ornithology; and July for Herpetology and Mammalogy... Check with the Academy of Natural Sciences for the full schedule of tours (and say hi to Fred if you go this month - that's him showing off the Mineralogy collection!).
The views expressed are those of the author(s) and are not necessarily those of Scientific American.