Some algae have chloroplasts and chlorophyll and obtain their energy through photosynthesis while some algae like euglena are both heterotrophic (decompose dead organic matter) and autotrophic (use photosynthesis) and can also obtain energy likewise.
Answer:
One reason is that there was too much pressure in the bottom of the ocean, from all the water pressing together.
hope this helps :)
Explanation:
Not sure but I think motor systems?
-Wulf
