Phylum Vertebrata has the most complex animals.
social animals
the most complex group of invertebrate is cnidarians
Because of their complex organs, circularitory systems, nervous systems, and gas exchange systems.
Segmented Worms
Society
A group of crows are called a murder ...
invertabates are the animals with the most extinctions
Insects
Anthropods is the largest and most diverse of all animals. These animals have segmented bodies that are supported by an exoskeleton. This group includes spiders, crustaceans, millipedes, and centipedes.
Australia
Insects
Sharks are the most obvious answer.