We’ve talked about how fossils form, how old they are, and even some famously strange ones… but there’s a big question that often gets asked, and one I've answered myself a couple of times now in the shop, so I thought it would be worth a write up!
“How do we actually know what dinosaurs looked like?”
So, this week’s Fossil Friday is all about the detective work behind it, and as I love alliteration, how we go from 'bone to beast'.
I’ve sketched a dinosaur in layers (skeleton / muscles / skin & feathers) as often it's this reconstruction order that gets us there.
Here’s how we get from the fossil to the full creature:
1. Start with the bones
The skeleton tells us the basics: size, posture indication, where limbs were attached, and how the animal could move it's joints. You can tell a sprinter from a plodder just from the leg proportions!
2. Follow the muscle scars
Bones often have tiny ridges and bumps where muscles, tendons, and ligaments once attached, and these are kept in the fossilization process. This gives scientists a “muscle map”, which lets them rebuild the body shape, using our general understanding of how muscles work gained from studying modern animals.
3. Compare with modern relatives
Birds and crocodiles are dinosaurs’ closest living family. By looking at their anatomy, behaviour, and soft tissues, scientists can 'fill in' details that don’t fossilize well, like the thickness of skin, placement of fat layers, and the shape of certain muscles.
4. Skin impressions & soft tissue fossils
Although super rare and definitely not available for all species, some fossils preserve actual skin texture, beaks, quills, or feathers. These snapshots tell us things like whether it had scales? Feathers? A beak? Spikes or armour?
5. Melanosomes = colour clues
I've mentioned these before in the post on trace fossils, but it's an important part of this process. In especially well-preserved fossils, scientists have managed to find tiny pigment structures called melanosomes, that hint at colours.
From these, we’ve learned that some dinosaurs had black feathers, grey tints, gingery-red patches …and even patterned wings!
No technicolour parrot style dinos have been discovered yet, but here's hoping!!
Then to go a little further, we can even get an idea of how they were as living breathing animals.
6. Behavioral fossils
Footprints, bite marks, healed bones, and nesting sites help fill in the blanks on how they lived. Did it run fast? Did it swim? Did it live in herds or alone? Did it care for young or kick them out to go fend for themselves?
Bones can definitely tell us what it was and how it might have looked, but it's the traces that tell us how it lived, and let's us get to know them.
Fun fact: Early dinosaur reconstructions from the 1800s often looked nothing like the real animals, some were built standing upright like kangaroos, others looked like giant toads! Have you seen the Crystal Palace sculptures?!
As more fossils were found, reconstructions became more accurate, which is why dinosaurs “change appearance” over time. We think we're pretty spot on now, but who knows what discoveries will come next!
