Dinosaurs Were Covered In Fleas
How insects evolved to bother giant beasts
Despite humans and dinosaurs never overlapping in existence, they had one thing in common; fleas!
Dinosaurs lived on Earth for 165 million years before going extinct roughly 65 million years ago. Humans only appeared about 5–7 million years ago. Instead, we live with the descendants of dinosaurs, like chickens, crocodiles, and sharks. Even if a shark isn’t as dangerous as a giant T-rex, they still share some DNA that made dinosaurs such formidable predators.
But what made dinosaurs so terrifying was their relative size. A Triceratops would have been 3x times larger than a human and a T-rex over 6x times. For reference, a human is about 5–6x times larger than a chicken. When looking at a T-Rex, we are roughly the size of a chicken! Watching Jurassic Park could also help with visualizing just how massive dinosaurs were. But just as the Megalodon would mammoth a modern-day shark, so were ancient bugs.
Insects entering the conversation
Long before even dinosaurs were on Earth, insects started emerging. The earliest insect fossils date back 480 million years ago. This is twice as far back as the earliest dinosaur fossil, a 233-million-year-old discovered in Brazil.
These bugs were MASSIVE too. An extinct ‘dragonfly’ species had a wingspan of up to 2.5 feet. Part of this was because there was simply more oxygen on the planet at the time, making it easier to sustain larger creatures.
It took another 150 million years for insect evolution to start rapidly producing new species. The key to this was flight. At the time, insects were the only flying species and so they rapidly evolved to start filling in different environmental roles. Flight allowed some to specialize high up in the trees while others more easily evaded other predators on the ground.
One such environmental niche involved blood because the first mammal appeared roughly 205 million years ago.
Primitive Fleas
Among those insects, fleas started to evolve. The mouthparts that allow a bee or butterfly to easily reach into a flower and drink nectar equally helped a flea drink blood. It just needed to be stronger to pierce through skin. The fossil of a primitive flea that existed more than 150 million years ago, thought to suck on dinosaurs, was found in China. Its mouth specially evolved to pierce through the thick skin of a giant dinosaur.
These ancient fleas were about 8x the size of modern-day fleas. While still massive, they couldn’t jump like modern-day fleas. Ancient fleas lacked the special spring-based legs that more modern fleas are equipped with. It was thought that instead of hopping onto prey, these ancient insects rather ambushed a victim by waiting. When a dinosaur or other large creature walked by, these fleas scurried and climbed onto the host.
Are dinosaurs to blame for fleas?
While it’s unfortunate to have dinosaurs to thank for fleas, it’s not entirely their fault. They just happened to exist at the time when fleas evolved and began sucking on blood. Dinosaurs also weren’t the only ones afflicted, any mammal or vertebrate with blood was at risk of developing fleas!
When evolution is a game of random chance, either developing a positive or negative trait, it’s a simple roll of the dice. In the case of fleas, it was pretty good for them — Not so much for humans with pets though.
