Question

what are protochordata?

Answer 1

the word protochordates means primitive chordata 

they posses notochord and some stages of their life . it stiff rod like structure that runs along the back of the organs and seperates and nervous tissue from gut .

marine animals
triploblastic 
bilateral symmetry
'U' Shaped or tubular

Answer 2

Prototochordata includes anyone of the nonvertebrate chordates, as tunicates, cephalochordates and hemichordates.

Protochordates do not have backbone.

They posses hollow dorsal nervecord ,gill slits .