Question

Animals were once categorized under a metazoan or eumetazoan. What makes the kingdom Animal Animalia and no longer a metazoan or eumetazoan?

Answer 1

Solution:

Animals were once categorized under a metazoan or eumetazoan.all multicellular organisms included in metazoan.but multicellular organism like trichoplax are not included in this.Eumetazoa also includes all major animal phyla except sponges, Placozoa.there many animals that not included metazoan nor eumetazoan.then Whittaker introduced kingdom animalia and included all animals all animals like sponges, trichoplax , animals without organs, all are included this kingdom.