What is the second largest phyla of animals?

What is the second largest phyla of animals?

• A. Mollusk
• B. Chordata
• C. Arthropoda
• D. Echinodermata

Answer: (A)

Think in terms of how many described species each animal phylum contains. Arthropoda is the largest by that measure, thanks to the enormous diversity of insects, spiders, crustaceans, and their relatives. The second largest is Mollusca, the mollusks, which includes snails, clams, oysters, squid, and octopuses. This group spans a wide array of forms and lifestyles, especially in marine environments, with a long and successful fossil record that adds to the tally of described species. Chordata and Echinodermata have far fewer described species, and Arthropoda is not the second largest. So Mollusca is the correct choice.

Think in terms of how many described species each animal phylum contains. Arthropoda is the largest by that measure, thanks to the enormous diversity of insects, spiders, crustaceans, and their relatives. The second largest is Mollusca, the mollusks, which includes snails, clams, oysters, squid, and octopuses. This group spans a wide array of forms and lifestyles, especially in marine environments, with a long and successful fossil record that adds to the tally of described species. Chordata and Echinodermata have far fewer described species, and Arthropoda is not the second largest. So Mollusca is the correct choice.