Ecosystem should be correct sorry if I am wrong
Characteristics of Lancelets:
Small
Elongated
Marine invertebrate
Lacks a jaw
No sense organs
Has a notochord
Example: Lamprey
Characteristics of Tunicates:
Marine invertebrate
Has an outer coat that is rubbery or hard
Has two siphons
Examples: sea squirts, salps
C - Eukaryotes and heterotrophic.
Good luck!
B. Thick Atmosphere
Let me know how it goes!