Posterior end of the spine is fused into a single bone called. ..?

Question

Science homework ..

I'm sorry. I seriously can't find this answer.

This is in the point of a frog

Answer 1

well it's the sacrum and then the coccyx (tailbone) in human.  Posterior means toward the feet while anterior means toward the head.  They're not exactly the same as inferior and superior, which are just relative terms.

maybe it's the same in a frog.