A six-year-old walks down the hall, eyes wide as he stares open mouthed at the skeletons towering high above him.  Dagger teeth, gleaming claws, curving necks and long, sweeping tails…It’s almost surreal how the bones are suspended in the air, as if the skin around them was just invisible.

Of course, now I know about the armature of steel.  How each bone has it’s own pocket to nestle in.  If one bone needs cleaning or repairs, then there’s no need to take down the whole skeleton.  But how do we know what the skeletons looked like?

In the last post, we talked about how unlikely it is to find a complete skeleton, or even a mostly complete skeleton.  If you haven’t read it yet, then check it out, because it’s pretty amazing what happens between dead dinosaur and museum. 🙂

But kid’s books and movies always show the whole dinosaur under some random hill.  It’s gotten downright ridiculous, so that Bob the Builder and his team can dig into a hill, find a complete skeleton of a brontosaurus “standing” in the dirt, and then simply leave it there to be the entrance to their dinosaur themed amusement park.

Convenient.

Truth is, building the complete skeleton is only the first part of figuring out just what these critters looked like.

It’s like the world’s toughest jigsaw puzzle, with a few minor complications…

• No box with the picture to get a clue on what you’re building
• No idea how many pieces there are supposed to be, just that there should be at least oh, 2,000 or so…right?  Just how many bones does your average dino have anyway?
• After a summer spent combing the hills, maybe this is what you end up with…

So what do you do?

Luckily, bones can tell you a lot, especially teeth.  An expert can tell you these are sauropod bones.  Even better, an expert can tell you these belong in the family brachiosauridae .

 

Now here comes the fun part…putting the puzzle together.

You look at all the other fossils in the family.  Maybe there are more of the same “genus”, brachiosaurus.  Maybe these bones are enough to tell which species of brachiosaurus you’re looking at, and you can look at those for reference.  And so on and so forth until you and your colleagues have determined what a complete skeleton of your brachiosaur might look like.

Of course, the whole process is a long, drawn out, very complicated business.  This is just my humble rundown. 🙂

Long story short- except in very few cases where paleontologists discover an articulated skeleton, like the lovely dilophosaurus here- then most skeletal reconstructions have at least a few missing parts, which are then filled in by educated guesses based on closely related animals.

Now that you have all the pieces, how do they fit together?

Knowing where all the pieces go relies on reference to other skeletons, research, and a great deal of know-how on the bones themselves.

Bones can tell us a lot, because the soft and squishy bits that hold them together leave scars.  Knowing how to interpret these scars is where dry bones get interesting, because this is the beginning of figuring out how the animal looked in life.

Next post we’ll talk about muscles, tendons, and all the soft stuff under the skin that we don’t usually see in the museum.

Quick Question: Did you like to see fossil exhibits as a kid?  What impressed you the most about them?  I’d love to hear your answer in the comments! 🙂

 

Fleshing out the Bones Series:

• Part 1: The Miracle of Fossilization (the crazy hard obstacle course from death to museum)
• Part 2: The World’s Toughest Jigsaw Puzzle (making a mounted skeleton out of bits and pieces)
• Part 3: Here’s the Easy Part (figuring out muscle and other fun anatomy)
• Part 4: Let’s Put Some Skin on That (how much we know, and don’t know, about the soft stuff)
• Part 5: Time to Get Wild! (how we can guess about behavior, and how crazy it can get!)
• Part 6: Uncharted Waters (all about the big picture.  No animal lives on a blank sheet of paper)