An actual 6 year-old asked me the question today. I was at a loss.
**Edit**: a lot of interesting answers, food for thought, and ideas on how to explain it to a child. Many thanks to the community!
If I summarize:
* Dinosaurs lived for a very (very) long time, all over the earth, and there were countless different species of them.
* There were few of our ancestors, from just a few species, and most of their existence was confined to limited geographical areas.
* The conditions for a fossil to form are extremely rare, and they may have been even rarer for our ancestors than they were for dinosaurs.
because dinosaurs lived for millions of years before they went extinct
while “humans” as we know it (including the prehistoric ones–our ancestors), have only been around for approximately ~200,000 years.
that’s a massive amount of time difference.
still, there are quite an amount of human fossils though https://en.wikipedia.org/wiki/List_of_human_evolution_fossils
Our ancestors were around for… 3-8 million years depending on what you consider an ancestor. Dinosaurs were around for at *least* 228 million years.
In addition to the lack of a mass extinction event to preserve large numbers of fossils, we just… haven’t been around very long.
For several dozen million years dinosaurs were the dominant kind of animals on the planet. That is, basically almost every medium- and large-size land animal was a dinosaur during that very long time period. While our ancestors have only existed for a few million years and constitute just a handful of species. And also for the most part of those years they’ve been confined to just one continent – Africa.
Three main reasons:
1. Dinosaurs roamed the Earth for millions and millions of years. Humans in any form have only been around for about 200,000 years. This means there’s lots more dead dinos than dead humans and proto-humans. LOTS more.
2. There were lots of different dino species and if we lump all dinos fossils into one collection, there’s going to be lots of them from lots of species in the fossil record. It would be a bit like lumping all primate species into one group even if they’re not human or proto-human.
3. Dino bones were huge, and big bones tend to fossilize easier compared to small bones. Also, big bones don’t get broken up and carried away easier, so there’ll be more fossilized more or less complete (or at least large chunks) of dino bones and very few intact human and proto-human bones.
No mass extinction event has occurred since proto-humans began to exist which caused simultaneous death and burial of these organisms.