We know that some turtles, sharks and whales can live way more than a century if not multiple centuries, but we don't know that because we have been following them from centuries.
There's a tortoise living on the Seychelle's governor garden since 1882 and has outlived every single governor yet.
We have a picture of it dating 1886: https://upload.wikimedia.org/wikipedia/commons/f/f0/Jonathan...
Is this just a fancy way to say that the tortoise is alive, and whoever was governor in 1882 is dead?
Which makes the “yet” weird, but I suppose it admits the possibility that the office might be restored before the tortoise dies, and the tortoise might not outlive the potential future governor.
That just feels like a long time to be a spider.
The interesting point here to me is that it was not killed before. This suggests that it was able to fend off the wasps attacks for fourty years. I assume that hen died it was too weak (too old) to fight back. Another possibility is that it had moult recently and was too soft to defend itself.
Insects die soon because adult wings can't moult twice. Spiders don't have wings so they can moult indefinitely and became much much older than insects --but-- is easy to predict that (unlike jellyfishes), spiders can't live forever
We can be 100% sure of this empirically. We even could predict mathematically the life time span of each species, also if we would want it (again, in my opinion).