How Bones Look

When I was about seven, I went hiking with my dad in Arizona, and we found some bones. For most people, this might have been a cause for alarm, but my father is a doctor, so he quickly reassured me that they weren’t human (much to my disappointment).

You’re probably thinking you don’t need an experienced physician to determine that, but you might be surprised by the number of calls police receive every year from people finding ‘human’ remains. Although size is often a major factor, there are plenty of animal bones that can be confused with human.

Confusing Animals

• Bears- Although bears look pretty different from us in life, their paws can strongly resemble ours when you get osteological.
• Raccoons- Again, it’s the hands. They just look like baby hands.
• Alligators- I’ve heard that their hands can resemble human hands, but I don’t personally see the resemblance. Their toes are very thick.
• Kangaroos- Unlikely to happen outside of Australia, though it may be, it’s pretty easy to see why kangaroo bones might be mistaken for human. They’re bipedal, only a bit bigger than us…The main differences are in the pelvis and the feet.
• Pigs- Usually the long bones (humeri, tibias, and femurs) are confused, as well as teeth. It’s no wonder we use pigs in so many tests since we’re so alike!
• Deer- Long bones and ribs from deer can sometimes be confused with human bones, but if you look closely, the ribs don’t curve as much in deer.
  

Major Differences
Teeth are hard to differentiate to the untrained eye, but it’s best to remember that most animals have much more specific diets than humans. Carnivores, for example, will primarily have teeth to rip, shred, and tear, so sharp long canines and incisors. Herbivores, on the other hand, specialize in grinding plant matter, so broad and flat teeth with lots of ridges.

For long bones, the main focus is quadrupedal vs bipedal movement. A human’s humerus (say that ten times fast) will always be thinner and more delicate than a large animal that needs its arms to bear weight…like, say, a bear.

In fact, lots of animals have evolved to fuse their radii and ulnae or their tibiae and fibulae (or both!). When those bones fuse, you can hold a lot more weight on the limb which is good for large animals. Why aren’t our legs like that too? Well, it has to do with the flexibility in our ankles and knees. 

If you’ve got ribs, just remember that we have pretty round torsos, so our ribs tend to curve a lot more than the rest of the animal kingdom, not just deer. 

Baffling Babies
On the flip side, the most common human bones to be confused with animal ones originate from infants. Babies don’t have fused epiphyses (ends of bones), which can make the main parts of the bones unrecognizable, even to experts. Cranial bones are frequently mistaken for turtle shells. Imagine making that kind of mistake!