. Which of these organisms are primary consumers? Birds, shrimp, worms
Mollusks, shrimp, fish
Mollusks, crab, birds
Mollusks, shrimp, worms

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen