This fossil must be younger than 475 million years old, because that is when land plants arose
Cells,tissue,organ organism,organ system
Answer:
Instead of a brain, echinoderms have a ring of nerves located around their mouth area that governs their nervous responses. This ring coordinates their motion, their eating, basically anything that requires nerve control.
Explanation:
Answer:
between 20,000 and 25,000
