Deuterostomia

## Temporal Range:

Rimunian - Today ("Stage 3" - Holocene) 519 - 0 Ma

## Subphyla

* †Thalamumsegmentia
* Echinoderma
* Chordata
	+ †Pingshuichthyidae
	+ †Liaopingichthyidae
	+ Vertebrata

Deuterostomia (second mouth in Zafuk), are animals typically characterized by their anus forming before their mouths during embryonic development. The sister group to the Deuterostomes are the Ecdysozoans. Some examples of Deuterostomes include chordates and echinoderms.

There are three major clades of Deuterostomes, they are the Echinoderms, Thalamumsegmentians, and the Chordates. Together these three groups and the ecdysozoans make up the Bilateria group.

## Systematics

### History

Initially, Deuterostomia did not include Echinoderms, because they were so outlandishly different than other living chordates. However, DNA analysis and comparison studies suggested that Echinoderms are most closely related to Chordates than Ecdysozoans.

### Classification

* Superphylum **Deuterostomia**
	+ Phylum Chordata
		- †Pingshuichthyidae
		- †Liaopingichthyidae
		- Vertebrata
			* Agnatha
				+ †Gnathodidae
				+ †Fuqiuichthyidae
				+ †Haleichthyidae
				+ Cyclostomata
				+ Ostracocephalida
					- Seijaspidae
						* †Patoaspida
						* †Domuaspida
							+ †Pteroaspina
						* Cephalaspia
							+ †Quinichthyida
								- †Palaeoceratoichthoidea
									* †Palaeoceratoichthyidae
										+ †Palaeoceratoichthyinae
											- †Akouwalepini
							+ Cephalaspoidea
								- †Eocephaloichthyidae
								- †Cephaloichthyidae
								- †Cephalspidae
									* †Cephalaspinae
									* †Leniscephalinae
										+ †Platycephalini
								- †Pseudosteoichthyidae
								- Gnathostoma
									* Placodermi
										+ †Pterichthyida
											- †Rericalepidae
										+ †Baryaspidae
										+ Arthrodira
											- †Titanichthyidae
											- †Kapikosteidae
											- †Omuvasteidae
											- Neenorasteidae
												* Haplopsopodamorpha
													+ Euhaplopsopoda
														- †Mianjingcephalidae
														- Haplopsopoda
									* Eugnathostoma
										+ †Comspinodia
											- †Comspinoidea
												* †Comspinodidae
													+ †Compspinodinae
										+ Chondrichthyes
											- †Pectopteryxidae
											- †Waysonidae
											- Eucarcharia
												* Pseudosqualidae
												* Carcharia
										+ Osteoichthyes
											- Sarcopterygii
												* Actinistia
												* Pulmoichthyiformes
													+ Pulmoichthyia
														- Tetrapodomorpha
															* †Meidongidae
															* Eubennastegalia
																+ ?†Tapazaherpeton
																+ Bennastegalia
																	- Tetrapoda
												* †Aputodontidae
											- Actinopterygii
												* †Paleoactinopterygii
													+ †Mianxingichthyidae
													+ †Donolaichthyidae
													+ †Chiboichthyidae
												* Saldobiidae
	+ Phylum Echinoderma
		- Asterozoa
			* Asterozoidea
				+ Asteroidae
		- Crinozoa
			* Palaeocrinoidea
				+ †Crinidae
					- †Bulbocrinidae
				+ †Palaeocrinidae
				+ †Crinitidae
				+ Graptocrinidae
		- †Schiffida
			* †Tricystidae
	+ Phylum †Thalamumsegmentia
		- †Sakdazoonida
			* †Sakdazoonina
				+ †Sakdazoonoidea
					- †Sakdazoonidae
		- †Khenboidea
			* †Khenbouidae