"Duckbill" is not the correct term; nor are they extinct. Platypuses are not even classified as endangered in 2014.
Millions of years ago .
The rock wren is still extant, not extinct.
Dinosaurs.
They were indians who lived a long time ago. They became extinct a long time ago too.
Because they are extinct a long time ago.
Plants.
I would say about 40000 years ago
dodo bird
because they got extinct a long time ago
No it is an adjective, extinction is the noun. Dinosaurs are extinct. The extinction of dinosaurs happened a long time ago.
3 years ago
If we all did what I do, pandas would have been extinct a long time ago.