0
$\begingroup$

I've heard they have mostly this:

  • central nervous system (nerve cord) on the ventral side of the body

Is that shared by both spiralia and ecdysozoans but different from the deuterostomes (where it is dorsal)?

Is there anything else aside from mouth-first vs anus-first?

Ecydosozoans have the cuticle, but it is not shared by spiralia, so while the cuticle is an apomorphy of ecdysozoans, it is not an apomorphy of protostomes.

Improve this question
$\endgroup$

0

Reset to default

You must log in to answer this question.

Browse other questions tagged .