Eli5 why do we find so many dinosaur skeletons but so few skeletons of our own ancestors like Lucy?


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.

In: 819

39 Answers

Anonymous 0 Comments

No mass extinction event has occurred since proto-humans began to exist which caused simultaneous death and burial of these organisms.

Anonymous 0 Comments

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.

Anonymous 0 Comments

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

Anonymous 0 Comments

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.

Anonymous 0 Comments

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.

Anonymous 0 Comments

There were a lot more dinosaurs over a much longer period of time than there have been hominins. The earliest hominins are something like six million years old, while the dinosaurs* were around for something like 135 million years. They were also distributed all over the globe while we spent much of that time exclusively in Africa.


* Speaking specifically about non-avian dinosaurs here, since I know someone will bring up the distinction.

Anonymous 0 Comments

The total number of dinosaurs was much greater than the total number of humans. Dinosaurs roamed Earth for about 165 million year, and there were about 700 species.

In contrast, the earliest known genus of the human lineage appeared on Earth about 5.8 million years ago. Lucy is a member of that species, but she was not part of the human species, and we aren’t even certain she is one of our ancestors. But assuming she is, the number of human ancestors is much, much smaller than the number of dinosaurs.

Anonymous 0 Comments

There are lots of dinosaur fossils because there were lots of dinosaurs living and dying across the entire Earth for a very long time, compared to a relatively short time and relatively few individuals in a small area for human ancestors.

The dinosaurs “ruled the earth” for almost 200 million years, starting in an era where all the modern continents were joined together in a single landmass, and “dinosaur” is a huge group that includes thousands of known species, and almost certainly millions of species that are either undiscovered or for which no evidence remains today. Lucy’s species, *Australopithecus afarensis,* existed for roughly one million years in one region of east Africa.

Dinosaurs are also helped by the fact that larger animals are more likely to be fossilized and survive into the present day, simply due to the higher durability of larger bones. An animal’s habitat also affects the likelihood of fossilization, as some environments are very destructive to deceased remains.

Anonymous 0 Comments

Lucy (*Australopithecus afarensis*) lived about 3 million years ago. The first things we’d look at and call “our ancestors” in that way aren’t much older, maybe 6 million years at most. Until *Homo erectus* these beings exclusively lived in east-to-south Africa and were a pretty small part of the ecosystem there.

Dinisaurs (excluding birds) existed for **200 million years** and for almost all of that time they were the dominant large life on the planet.

So not only have we been around for, like, 1/40 the time as they were, but we’re also a handful of species that lived in one small part of the world for most of that time. ‘Dinosaur’ isn’t one lineage like hominids – ‘dinosaur’ means *millions* of species over that time, in every possible niche – big, small, apex predator, little bug eater, jurassic equivalent of a cow, etc.

There’s LOADS of individual dinosaur species that have less fossil evidence than Lucy’s species – most are known from only one single fossil find.

Anonymous 0 Comments

There have been a lot more dinosaurs than humans on the planet. In terms of how long dinosaurs were on the planet compared to how long we’ve been on it, it’s like comparing how long someone’s eyes are closed while napping (the dinosaurs) vs someone blinking (us).

So there’s just a lot more dead dinosaurs to find than dead humans.