Question

What are prechordate their characteristic and why ptrebranchian are called acorn worms

Answer 1

They are known as acorn worms because of the appearance of the proboscis and collar. Pterobranchs (about 20 species) are minute, colonial, tube-building forms. Planctosphaeroidea are known only from a few floating larvae.

Answer 2

They are known as acorn worms because of the appearance of the proboscis and collar. Pterobranchs (about 20 species) are minute, colonial, tube-building forms. Planctosphaeroidea are known only from a few floating larvae!