恐龙不是已经灭绝了吗? 这句话英文怎么翻译?

以下两种形式都可以：

Haven't the dinosaurs died out？

The dinosaurs have died out，haven't they？

恐龙群体都已经灭绝了，所以要用复数，并且要用现在完成时的反义疑问句。

Didn't the dinosaur die out?

wasn't the dinosaur extinct?