I recall hearing that those amazing dinosaur skeletons in museums are almost never the actual fossilized bones, but instead they are casts made from those bones. I think the explanation was that the real fossil bones are too precious, too delicate, and too heavy to mount in a big display.
(I know that sometimes in a display there will be an indication that certain bones were not found and those are clearly indicated as just filler, with a different color or something. I’m not talking about that.)
So my question is this: Is that accurate? And if so, how common is this? Do museums ever display the real, actual, this-is-what-we-dug-out-of-the-ground-and-it’s-really-a-million-years-old bones?
And a follow-up: If they’re displaying just a resin cast of the bones, doesn’t that take all the fun out of it? Standing inches away from something that is millions of years old is very different from standing next to some plastic that looks exactly like something millions of years old.
Yes, the mounted skeletons on display are often casts - in older ones, plaster instead of resin. The motivation for this is in part to have the actual specimens available for study, and in part to reduce the weight of the mounted skeleton. However, this is not always the case, and often what is on display is the original fossil (especially when it is in a glass case). Often you will see small signs in a display where the original fossil has been removed temorarily for study; if it were a cast this would be unnecessary.
However, what is on display, although the origianl fossil, is often not the original bone. Instead, the fossil has become “petrified,” that is, the original bone or other organic substance has dissolved and become replaced by minerals while it was buried, leaving an exact replica in its place. (This is why fossil “bones” can be much heavier than real bones.)
It depends on the rarity of the specimen (and, I suppose, the budget and prestige of the museum). I was disappointed to learn that the famous Diplodocus skeleton in the central hall of London’s Natural History Museum is a replica, but they do have some genuine skeletons on display and others that are partially genuine with missing parts replaced by castings, but in a different colour.
The old ones definitely are. In the American Museum of Natural History, the T. Rex skull was a cast, simply because when they put it up it was one of the few (and one of the best) skulls they had, and they didn’t want it to fall and break (and probably didn’t want to drill holes in it for mounting). The real skull was on display in a case next to the full skeleton.
They certainly used to use casts and reconstructions in models (they’re never fully complete), but my understanding is that they did put the actual bones on display.
I think they’ve been getting away from this in recent years, for several reasons:
1.) he original fossil bones are pretty valuable pieces of information. In order to put the bones on display, you’d have to drill massive weight-bearing holes in them (the fossils, after all, are solid rock, and are even heavier than the original, pre-permineralized bones were). That effectively throws away fosilized bone that would be useful for bone histology studies, among other things.
2.)If the bones are on display, they can’t be used for study. No one wants to lock up a valuable information resource.
3.) New methods, such as computer modeling, allows more flexibility ion completing skeletons. Instead of putting a head from another fossil in place (as happened with brontosaurus/apatosaurus way back), you can model a new head mathematically and then use the data file to generate a model via that 3-D lithography. They did this for “Sue”, the recent T. Rex skeleton. The original skull was deformed and crushed by geological forces, but they were able to map it using a CAT scan or something, then mathematically unsmoosh it. They made a new model of the pristine skull, which was mounted for display. Similarly, at the Smithsonian they had a triceratops skeleton that lacked a head. They could’ve used another head from elsewhere, but these generrally aren’t the right size for the body. They created a properly-sized skull for their mounted skeleton.
All the explanations for why they sometimes use casts make sense, but I sense some unfair deception here. I think most people assume those amazing skeletons are the real thing, because otherwise, what’s to get excited about? I can go to an amusement park and see some pretty cool pretend dinosaurs.
Maybe the tour guides admit the truth if pressed, and maybe you can find some info posted that they’re casts and not the real thing, but I suspect museums know that the average visitor is going to assume they’re the real thing and don’t want to discourage that assumption.
After all, people aren’t going to flock to a museum to see plaster and resin because there’s nothing special about it. You could, theoretically at least, make a thousand casts and let every high school put a T-rex in their football end zone. A cast of something precious and unique is not precious and unique. But seeing the actual skeleton, that’s special.
I never like it when people benefit by allowing others to make a natural, reasonable assumption that in fact is not correct.
Awesome. I want a t-rex in my high school’s endzone!
“Fossils” is a big and awfully general term. The OP seems to be talking about giant displays of dinosaurs, but there are millions of fossils of every possible kind, from one-celled animals on up.
There are so many fossils that backrooms of museum tend to be stuffed full of fossils that just can’t be displayed or studied for lack of space and time. Some interesting results have been made by pulling out these old drawers full of fossils and looking at them again with modern eyes.
And displays aren’t permanent. They change and rotate. I remember being in Cleveland when the original Lucy skeleton was put on display. As long as this is temporary and the skeleton can be returned to the lab for later testing there’s no necessary barrier to having a fossil be both on display and not at various times.
In my experience, museums have been filled with more authentic fossils than I could take in. You can’t limit the hundreds of millions of years of the past to just a few huge gaudy eye-catching specimens.
Exciting new development, Col! A young paleontologist recently convincingly argued that a whole lot of the fossils of dinosaurs is made of the original bone.
That is, the bone has changed to rock; however, lots of the complex molecules appear to be the same guys as were in the living breathing dino. Like, they’re finding things that look like red blood cells.
Google on “T rex soft tissue” and you’ll find tons of articles.
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The May issue of Smithsonian had an excellent in-depth article:
http://www.smithsonianmagazine.com/issues/2006/may/dinosaur.php
The answer of course is “no”. They are clever fabrications placed there 5000 years ago by God to test our faith.
Point taken. But museums know that the average person does focus on the few huge gaudy eye-catching specimens. And if they aren’t the real thing, they shouldn’t let people think they are.
And they don’t usually put the one-celled animal fossils on those banners flying from the lamp posts all over town.
Do you have any evidence that any museum displays large fossil skeletons that are replicas without telling the public about it?
Nobody, including you, has offered even a single example of this practice.
If it doesn’t happen, then you don’t have much of a target for your umbrage. If it does, then name names.
Here are the steps taken in making a reconstructed skeleton of a T-Rex, from the Carnegie Museum in Pittsburgh:
http://www.carnegiemnh.org/ditw/paleolab/samson.htm
And if I recall correctly, even some of that precious soft tissue was put on display (behind glass, of course). I’ll try to remember to stop by the Museum of the Rockies in the next few days, and check. It’s really cool when Bozeman shows up in the international news like this :).
From the American Museum of Natural History site (www.amnh.org ):
All of the examples I give in my post were identified as casts by signs at the museum, so I don’t think there’s anything sneaky going on there. (On the other hand, if they didn’t tell me, I wouldn’t know, right? I don’t know which 15% of the AMNH “fossils” are casts, offhand. But most museums seenm to be upfront about it.)
I’ve seen them making casts at the AMNH. Full-size high-quality fossils of many species are rare, so this gives smaller museums a chance to put on display, say, a Triceratops skeleton.
The cute baby Stegosaurus skeleton on display at Dinosaur National Monument is a cast. The original is such a rarity that it’s stored away. They tell you it’s a cast. (The fossils in the shelf wall at Dinosaur are obviously real, and can’t possibly be casts – they’rer still half-embedded in the rock. They include a baby diplodocus)
Fossils that are relatively plentiful get put on display because there’s less import if they get broken, and removing them from study doesn’t cause any hardships. There are a lot of allosaurs on display, in part because the Cleveland-Lloyd Dinosaur Quarry in Price, Utah produced so many of them. (It’s thought to have been like a La Brea Tar Pit situation where plant-eaters got stuck in the mud, which lured the carnivorous allosaurs, who then themselves go stuck in the mud, and everyone got buried together.)
No no, God would never create the evil monsters that supported that gol’durned theory of evomolution! They were made by the devil, so they were!
Another big factor in using casts is that complete skeletons are almost never unearthed. They have to use casts to fill in the gaps.
I used to work at the Science Museum of Minnesota and the triceratops on display there is more than 80% real fossil. The bones come from two individuals with the rest being casted. It’s the best mounted triceratops in the world.
If you ask the employees about the casts they will produce cards that show which bones are casted and which are real fossils. They have such cards for all the big dinos there. Furthermore, there are hands-on areas where visitors can touch real fossils.
I can’t comment on your feelings about the perceived “deception” but I have to say, as a dinosaur enthusiast and artist, I am very much grateful for the availability of cast skeletons (especially those made with modern casting methods that render an almost perfect replica of the appearance of the original fossils) and I can and will get very excited when I get a chance to see even a replica of a rare and beautiful specimen - or even a relatively common specimen. Otherwise I’d never get a chance to see Archaeopteryx as anything other than a photograph or drawing, I wouldn’t be able to see a LOT of the specimens without traveling all over the world. Would be fun, but a little too expensive and time-consuming for my tastes.
I don’t usually get excited about the age of the bones or whatever; I don’t sit there and think, “Wow, this skeleton is 65 million years old!” Maybe that’s because I’ve been a dinosaur enthusiast for so long; I can appreciate the deep time aspect, but I’m more interested in figuring out the biology, appearance and behavior of the animals in question. That being said, I realize that for many people, it does make a big difference if they are the real bones or cast replicas on display; I think I’m sometimes as baffled at that attitude as the other people might be baffled about my indifference to the cast/real fossil issue.
My point is, to some people (myself included), seeing even the cast replicas is special and worthwhile.
It’s not quite an example like the OP has in mind, but, in my experience, the Archaeopteryx specimens illustrate how different museums can treat the issue differently.
The Natural History Museum almost invariably never has the London one on display. Instead, there’s a good cast and an explanation of how the requirements of making the original available to researchers prevent them displaying it. They did include both halves of the slab when they hosted the (brilliant) exhibition of recently discovered Chinese dino-bird fossils that has toured internationally.
The Museum für Naturkunde has the Berlin specimen itself routinely on display in a special case in their main hall, together with an explanation of its significance.
The Tyler Museum in Leiden has theirs as virtually just another fossil amongst lots of others in one of their old-fashioned display cases. I suspect 99.9% of the visitors don’t even realise it’s there.
I remember reading (but don’t remember where) that there have been only 11 T-Rex skeletons found. That means they HAVE to put up “fakes” everywhere else, 'cause EVERYBODY wants to see a T-Rex, darn it!
If somebody can find a cite regarding this, I’d appreciate it. It might convince me that my brain has not yet become fossilized. 
Third paragraph:
The article is dated 1997, so I think a few more may have been found since then, but the number is certainly quite small. As a top predator, T. rex would not be expected to be very abundant.