You’ve probably seen the gaping jaws of Otodus megalodon (or “megalodon,” as it is colloquially known) in a natural history museum. Perhaps they’re set on the ground where they can frame a group photo, or maybe they’re suspended from the ceiling so you can imagine the rest of the shark rocketing toward you. In any case, every one of these O. megalodon jaws is a sculpted model with real (or cast) teeth embedded in it. Fossil jaws like this have never been found. Nor do scientists expect to ever find intact O. megalodon jaws—shark skeletons are made of cartilage, meaning they lack the mineral content and endurance of bone. Some fossilized shark skeletons are known, but they tend to be from smaller varieties. In the case of O. megalodon, we mostly just have teeth.
Why would a museum display a model of something that has never been found? Because paleontologists are quite confident that a real O. megalodon jaw would look just like this. For one thing, the general shape of modern lamniform shark jaws isn’t especially variable. Comparisons with modern sharks also allow scientists to determine where a fossil tooth fits into the mouth—in the front, to the side, or toward the back. There simply isn’t that much room for guesswork in the reconstruction, at least as far as the jaws are concerned.
I’ve been thinking about the accusation of “fake” again, as it pertains to fossil exhibitions (this is hardly new territory for this blog). One often hears from dissatisfied members of the public that the fossil skeletons on display at any given museum are fake—sometimes with the accusation that the real bones are “hidden” or “in storage” but occasionally with the conspiratorial angle that the creatures on display have been partially or fully invented. Museum workers do their best to explain: casts are exact copies made from molds of original fossils. Fossil skeletons are usually incomplete, but we can substitute casts from other individuals or mirror parts from the opposite side of the body. Plenty of mounted skeletons are made of original fossils, and at bigger museums, most of them are. And so forth.
And yet, the cry of “fake” isn’t exactly wrong, either. Many displays contain some amount of sculpted material. In the case of the ubiquitous meg jaws, most of the object by volume is reconstruction. Lukas Rieppel cheekily describes early 20th century dinosaur mounts as “mixed media sculptures, having been cobbled together from a large number of disparate elements that include plaster, steel, and paint, in addition to fossilized bone.” He’s right, and what’s more, even complete skeletons don’t come out of the ground assembled on metal armatures.
So here’s my take: calling fossil mounts fake isn’t wrong, but it also isn’t relevant. The point of the O. megalodon jaws at the start of this post isn’t to show you the real fossil teeth—they’re kind of hard to see suspended fifteen feet off the ground. No, the point is to give the extinct shark that left those teeth behind form, life, and context. The visual and visceral experience of a 10-foot mouth rushing down at you provides a better understanding of what O. megalodon was all about then a case of teeth laid flat in a case ever could.
The same applies to just about any mounted fossil skeleton you’ve ever seen, whether it includes original material or is entirely cast. The purpose of these displays isn’t to show fossils as they were found. These are works of installation art, custom built for the space and in dialogue with their surroundings, including with visitors themselves. Take SUE the T. rex in their 2018 gallery on the Field Museum’s second floor. When SUE was in the cavernous, half-acre expanse of Stanley Field Hall, visitors often remarked that SUE looked small. In order to emphasize SUE’s size in the new space, the designers hid the skeleton behind a scrim wall. Instead of first seeing SUE from several hundred feet away, visitors don’t meet the T. rex until it’s looming over them, and they feel quite small in comparison. The T. rex skeleton and the space around it were arranged and composed in order to invoke a precise emotional response.
Often, the display evokes a specific hypothesis. The rearing Barosaurus in the AMNH rotunda is a classic example. We don’t know for sure whether Barosaurus could rear up on its back legs, or whether it would defend its offspring from a charging Allosaurus. But this is the story the exhibit’s creators chose to tell, using articulated fossil casts as their medium. In short, a display like this lets visitors without a detailed background in skeletal anatomy and animal behavior see the fossils the way that scientists do.
It’s worth drawing a comparison between mounted fossil skeletons and the other iconic natural history display, the taxidermy diorama. Imagine looking at this exquisite diorama of a rolling bison at the Denver Museum of Nature and Science, and dismissing it because it’s not real. The bison is, for the most part, a fabrication: it’s mostly clay or foam by volume, and it’s built over a wood and metal armature. It has no bones, muscle, blood, or viscera, and the only original part, the hide, has been treated with an assortment of preservatives. Meanwhile, the grass may well be paper or fabric, the background landscape is a painting, and the warmth from the sun is an electric light. This diorama is almost completely fake, but to say so is to entirely miss the point. If physical reality is all that matters, this display has nothing to offer that you can’t get from a leather sofa.
A well-made taxidermy diorama uses artificial materials to evoke the attitude, behavior, context, and essence of a living animal. A reconstructed fossil skeleton does precisely the same thing (although it is limited to the part of the extinct animal that we know best). So the next time someone dismisses a fossil exhibit as “fake,” try reframing the conversation. The reality of these displays doesn’t come from the material they’re made from, it comes from the combined knowledge and skill of preparators, artists, and scientists.
References
Rieppel, L. 2019. Assembling the Dinosaur: Fossil Hunters, Tycoons, and the Making of a Spectacle. Cambridge, MA: Harvard University Press.
Poliquin, R. 2012. The Breathless Zoo: Taxidermy and the Cultures of Longing. University Park, PA: The Pennsylvania State University Press.
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