How Do Scientists Know What Dinosaurs Looked Like?
Picture this. You’re out in sun-drenched territory in Morrison, Colorado. As you stop to close your eyes and take a deep breath in the searing heat and wipe another steady stream of sweat from your face, you notice a rock that seems a bit different. It’s hard to see it at first, but the color, texture, and placement seem a bit off in its surrounding. You clamber over the terrain separating you from this object of intrigue, keeping your gaze locked on the exact spot you noticed when you first opened your eyes from that deep breath. Now that you’re at the spot, you believe that your suspicions are correct. This rock seems to be more than just a rock. With your field gear, you begin to excavate carefully around the rock, slowly revealing what can be clearly identified as a fossilized jaw of some prehistoric creature. Excited that your amateur paleontological journey has paid off, you ask yourself while staring wide-eyed at your discovery, “What was this and what in the world did it look like?”
While we all may not be in that position in our lives, if you’re a fan of dinosaurs and other amazing prehistoric creatures, you may have imagined yourself in this situation. You could make the find of the century somewhere! You’re more likely to have this daydream after watching a documentary or Jurassic Park movie where these amazing creatures are brought back to life on the screen.
The question remains: How do those fossils go from that exhilarating moment of discovery to become a classified, named, and fully imagined drawing or computer model of a dinosaur? Between discovery and depiction, there is a lot of scientific sleuthing and artistic licensing that comes into play. Over the course of the past several decades, our understanding of dinosaurs has changed dramatically and so has their depictions. From bipedal, lumbering, tail-draggers to intelligent, complex, and sometimes feathered beasts, a lot has changed in our understanding of dinosaurs. How we depict dinosaurs has also changed to reflect these new understandings.
2 - An eye for clues.
Careful observation of your fossil can lead you to a lot of very useful information. For example, the teeth in a fossilized jawbone can tell you the diet of your organism. This information can lead you to the part of the phylogenetic, or “family tree” where the dinosaur belonged. Phylogenetic trees are a way of visualizing evolutionary relationships between a group of organisms that share a common ancestor. A phylogenetic tree branches out as new species or groups of species are formed with their own unique traits. This can be incredibly helpful as members of similar branches of the tree will have similar traits. The phylogenetic tree on page 7 of your Dinosaur ID Guide shows which dinosaurs were alive and during what time. The names and numbers on the left side of the sheet indicate what era and how many million years ago they lived. You’ll notice that not all of the dinosaurs you’ve heard of are on the diagram. Some you’ve heard of before were alive during the entire age of dinosaurs. For example, Ceratopsia, the group where the Triceratops belonged, appeared first in the late Triassic at the earliest.
3 - Environment.
Based on the location of the fossil and the relative age of the rock, you can learn about that location’s environment during the time that dinosaur was alive. The world has changed in an incredible amount of ways over time. Using Howard Hughes Medical Institute’s Earth Viewer, move back in time to see a location and details about that location back when your dinosaur was alive. For example, the location of Los Angeles during this time period is no longer coastal area, but in a mountainous area. That type of environment could therefore be a potentially colder and rockier environment than exists there now.
4 - Look deeper.
When there is very little fossil evidence, paleontologists take a much deeper look. Microscopic details in the structures of the bones can lead them in the right direction to identifying their dinosaurs. Minute details can mean big things to paleontologists, whether it be places for feathers to connect or channels for air sacs. Paleontologists also know the value of collaboration and what it means to support each as they make new discoveries.