Subkingdom Eumetazoa

Tree of Life

Eumetazoa

True Organized Tissue

Also see:
Simplified Tree of Life Suitable to Organized Fossil Record

Cambrian Explosion
Small Shelly Animals (Tommotian Fauna)


Eumetazoa is a eukaryote clade in Kingdom Animalia containing all major animal groups except sponges, placozoa and several other animals groups about which little is known. The differentiating haracteristics of eumetazoans include true tissues organized into germ layers, and an embryo that goes through a gastrula stage. Most scientists include Ctenophora, Cnidaria, and Bilateria in the subkingdom, but placement within of mesozoans and placozoans is disputes. Phylogenetic research using the molecular clock approach to molecular evolution as well as study of the fossil record suggest suggests eumetazoa evolutionary origins in the Ediacaran Period of the late Proterozoic. Other interpretations exist.

Clade
Contained Within
Phyla or Groups Contained
Defining Characteristics and Fossil Examples
Radiata Domain Eukaryota
Kingdom Animalia

Subkingdom Eumetazoa
Radiata (unranked)
Ctenophora
Cnidaria

The Radiata are the radially symmetric animals of the Eumetazoa subkingdom.
Bilateria Domain Eukaryota
Kingdom Animalia
Subkingdom Eumetazoa
Bilateria (unranked)
Orthonectida
Rhombozoa
Acoelomorpha
Chaetognatha
Have bilateral symmetry, i.e. they have a front and a back end, as well as an upside and downside.
Superphylum Deuterostomia

Domain Eukaryota
Kingdom Animalia
Bilateria (unranked)

Chordata
Hemichordata
Echinodermata
Xenoturbellida
Vetulicolia (extinct)
 Deuterostomes are distinguished by their embryonic development; in deuterostomes, the first opening (the blastopore) becomes the anus, while in protostomes it becomes the mouth.
Superphylum Ecdysozoa Domain Eukaryota
Kingdom Animalia
Subkingdom Eumetazoa
Bilateria (unranked)
Protostomia (unranked)
Kinorhyncha
Loricifera
Priapulida
Nematoda
Nematomorpha Lobopodia (extinct)
Onychophora
Tardigrada
Arthropoda
 The most notable characteristic shared by ecdysozoans is a three-layered cuticle composed of organic material, which is periodically molted as the animal grows. This process of molting is called ecdysis and gives the group its name.
Superphylum Platyzoa Domain Eukaryota
Kingdom Animalia
Subkingdom Eumetazoa
Bilateria (unranked)
Protostomia (unranked)
Platyhelminthes
Gastrotricha
Rotifera
Acanthocephala
Gnathostomulida
Micrognathozoa
Cycliophora
Having a shared characteristics such as the structure of their jaws and pharynx.
Superphylum Lophotrochozoa Domain Eukaryota
Kingdom Animalia
Subkingdom Eumetazoa
Bilateria (unranked)
Protostomia (unranked)
Sipuncula
Hyolitha (extinct)
Nemertea
Phoronida
Bryozoa
Entoprocta
Brachiopoda
Mollusca
Annelida
Echiura
Molecular sequencing small-subunit ribosomal RNA (rRNA) supports the monophyly of these clades.