Society
the most complex group of invertebrate is cnidarians
The largest gland is liver and most complex organ is brain .
Insects are the largest and most common invertebrate group.
Phylum Vertebrata has the most complex animals.
Knee
The Arthropods are the largest and most diverse.
the biosphere
The cerebrum is the largest and most complex part of the human brain.
It is Insecta.The largest group of arthropods are aquatic, so things like shrimp, lobster, (and the most popular) Crab.Crab is the largest group in the arthropods.
Segmented Worms
Cnidarians are the most diverse group.