Asked by Angie

Which life-form was most abundant 250 million years ago?

a. dinosaurs
b.reptiles
c.bony fishes
d.trilobites

I think it's d.
Answered by bobpursley
well, they were abundant until they died out about the 250 million years ago.
Answered by Angie
then what is it supposed to be, reptiles?
Answered by bobpursley
I would do with d, assuming they didn't die out then, but at 249million years ago.
Answered by Angie
oh ok
Answered by Count Iblis
Trilobites became much less abundant earlier, see here:

http://en.wikipedia.org/wiki/Trilobite

They died out completely 250 millions years ago.