Thread: Humans = a new guide fossil?

We know Trilobites existed in the Paleozoic and were spread around the whole planet, we also know they didn't exist very long.

The same goes for ammonites, they were spread around the whole planet and they didn't exist very long.


What if they died out because they distorted the ecosystem too much?

Would that mean men will die out too since we are also spread around the whole planet and we don't exist very long (yet) and of course, we are messing up the system quite a bit...

except that there were thousands of trilobite and ammonite species, and only a handful of hominids
also, trilobites and ammonites lived in the sea on continental shelves, where the prospect of fossilisation is far higher than for far less numerous land vertebrates

Originally Posted by Aero

We know Trilobites existed in the Paleozoic and were spread around the whole planet, we also know they didn't exist very long. ...

They existed from early Cambrian (521 mya) to end Permian (251 mya). That's 270 million years. That's more than four times the duration since the demise of the dinosaurs. I think that qualifies as a long time.

Originally Posted by Aero

The same goes for ammonites, they were spread around the whole planet and they didn't exist very long. .

They first appeared in the Devonian about 270 million years ago and went extinct along with the dinosaurs 65 million years ago, for a longevity of 205 million years. Again, that's a pretty long time.

Marnix's points are also valid.

Originally Posted by Aero

We know Trilobites existed in the Paleozoic and were spread around the whole planet, we also know they didn't exist very long.

The same goes for ammonites, they were spread around the whole planet and they didn't exist very long.


What if they died out because they distorted the ecosystem too much?

Would that mean men will die out too since we are also spread around the whole planet and we don't exist very long (yet) and of course, we are messing up the system quite a bit...

Hmm define "didn't exist very long".

Trilobite, aka members of the Class Trilobita, lived from the Early Cambrian to the end of the Permian, 530–251.4million years ago. Thus as a group they lived for 278.6 MIllion years

Ammonoidae, the subclass containing ammonites, goniatites, and ceratids, lived from the Silurian to the end of the Cretaceous, 425–65.5 mya, a span of 395.5 million years

In contrast Superfamily Hominoidea, the group containing all apes, arose at 28.4 milion years ago, and the family Hominidae, Homo sapiens and relatives, have only been around for 7 million years.

Thus the homonids have lived for 2.5% of the time trilobites did and 1.7% of the time Ammonites did.

Another factor is the way the groups died Ammonites were wiped out with 60% of all life on the plant most likely by either an asteroid impact, eruption of the Deccan traps flood basalts or a combination of the two.

While not as defined, the Permian extinction is thought to have been caused by the opening of the Atlantic ocean and the activity of the central Atlantic Magmatic Province.

i've taken Aero's point to mean that many individual trilobite or ammonite species tend to be geographically widespread and restricted in time, which makes them suitable as index fossils

but in order to be a truly useful index fossil, the species has to (1) numerous and (2) widespread
we may be widespread, but despite appearances 10 billion humans is a small number compared with the number of trilobites and ammonites alive at any one time (at least in their heyday)
+ as i've said before, trilobites and ammonites stand a far better chance of ending up in the fossil record

Would our burials increase the odds we'd leave behind our fossils?

In any case, we'll definitely leave behind plenty of evidence of our existence. Long ribbons of gravels and tars that make up our roads, huge piles of concrete and rust from where our buildings once stood, enormous stretches of flattened terrain were we tilled fields of dragged our coastal waters for fish, a sharp spike in Co2 that last for tens of thousands of years, a mass extinction of most mega fauna combined with a global dispersion of species we used or kept as pets...just to name a few.

Land fill sites, to add to your list.

I didn't know they existed for such a long time, in our manual there are no real time indications and it says they didn't exist very long (so i assumed this was right)


Thanks for the many, helpful replies!