Archaeodesmostraca

### Habitat

Primitive forestCrescentia (range also spanned most of the supercontinent before the platydonts evolved)

### Emergence

4187ma (diverged from Eudesmostraca sometime after 4198ma)

## Taxonomy

Anthostoma

Gastrozoa

Tentaclostoma

Neostoma

Lophostoma

Diplostoma

Stenostraca

Desmostraca

**Archaeodesmostraca**

## Immediate subtaxa

Notoformes

Archaeodesmostracidae

**Archaeodesmostraca** (lit. "old desmostracans") is a clade of basal desmostracans. All members of this clade, save the notoformes, were driven to extinction by the platydonts.

## Description

The archaeodesmostracans were the first desmostracans, evolving from the original stenostracans in response to the emergence of the first predatory coleostracans.

Like their stenostracan ancestors, these early desmostracans tended to be adaptable omnivores, feeding on anything from malacoformes to caulophytes, and maintaining a relatively mobile lifestyle. As they were more selective in their feeding than other diplostomes, they evolved a pair of antennae tipped with chemical receptors to search leaf litter for anything edible. Like all desmostracans, each archaeodesmostracan possessed a characteristic banded shell, which granted it a fair degree of protection without significantly impeding its movement. In many species, this banded shell even allowed individuals to curl into a defensive ball.

### Decline

Like the other two major diplostome clades of the time, the early desmostracans were negatively affected by the emergence of the osteopods. The desmostracans in particular were outcompeted by the platydonts, which came to dominate the niches of adaptable opportunists. The only known surviving members of the clade Archaeodesmostraca are the notoformes, which descend from a group of desmostracans that rafted to Crescentia before the platydonts evolved. All other species, which are considered to be part of Archaeodesmostracidae, have gone extinct.

## Navigation

* **Anthostoma**
	+ Archeanthostoma
	+ Gastrozoa
		- Eugastrozoa
		- Tentaclostoma
			* Lithostraca
				+ Eulithostraca
				+ Anostraca
			* Neostoma
				+ Myzostoma
					- *Pelonomus thomi*
				+ Lophostoma
					- Diplostoma
						* Placostraca
							+ Archaeoplacostraca†
							+ Euplacostraca
								- Euplacostracidae
									* Euplacostracine
									* Echinostracinae†
								- Xerostraca
						* Stenostraca
							+ Eustenostraca
								- Desmostraca
									* **Archaeodesmostraca**†
										+ Archedesmostracidae†
										+ Notoformes†
											- Archenotoformes†
											- Neonotoformes†
												* Thyreostraca†
												* Campylospondyli†
													+ *Erythrerpeton lequiori*†
									* Eudesmostraca
										+ Eudesmostracidae
											- Eudesmostracinae
											- Myxobolidae
										+ Dolichostraca
											- Pronocanthidae†
												* Eupronocanthidae†
												* Phylactocanthidae†
											- Eudolichostraca
												* Eudolichostracidae
												* Nothocanthidae†
							+ Coleostraca
								- Archaeocoleostraca†
								- Elastospondyli
									* Archelastospondyli
										+ Archelastospondylidae
										+ Kentrodontia
											- Eukentrodontia
												* Archekentrodontia
													+ Archekentrodontidae
													+ Neokentrodontia
														- Trypophora
														- Deinoglossidae
												* Phyllophora†
											- Aspidontia†
												* *Kremarapax mckinleyi*†
									* Opisthoptera
										+ *Eopteryx emmetti*
										+ Archeopisthoptera
											- Latoptera
												* Eulatoptera
												* Pipiodontia
													+ *Corvimimus corvusamousi*
													+ Archepipiodontia
													+ Pterolophidae
											- Picoptera
												* *Gyriphagus oelespi*
										+ Neopisthoptera†
											- Sphenoptera†
												* *Velocialatus alexani*†
											- Magnoptera†
												* Eumagnoptera†
													+ *Skotalatus rauli*†
												* Dyptopterida†
													+ *Tachynectes jocomoli*†
					- Malacoformes
						* Echinostoma
						* Eumalacoformes
							+ *unspecified*
								- Ctenognatha
									* Euctenognatha
									* Necroformes
								- *unspecified*
									* Barognatha
									* Aciculognatha
										+ Euaciculognatha
										+ Chlorodermata
							+ *unspecified*
								- *unspecified*
									* Onychognatha
									* Mastigognatha
								- Isognatha
									* Myzognatha
										+ *Vitapatatoria aspiana*
									* Euisognatha
										+ Archeisognatha
										+ Cyanodermata

* **Polypodia**
	+ Tetrabrachia
		- Tachypodia
		- Acanthopodia
			* Orthorhachia
				+ Tanypterida
				+ Remipterida
					- Arheremipterida
					- Synopteridae
			* Hadrorhachia
				+ Ptilopoda†
					- *Bathytitan vendari*
				+ Euhadrorhachia
					- Diplocirridae
						* Archediplocirridae
						* Astrapophora
					- Teleopterida
						* Dorypoda
							+ *Kamakivenator cosmici*
							+ Archedorypoda
							+ Xiphopoda
						* Temnopoda†
							+ *Teratodectes iasoni*
	+ Sarcopodia
		- Coelopoda
			* Eucoelopoda
			* Trichopoda
				+ *Prionorostrum aegisari*
		- Neopoda
			* Metaxypoda†
				+ *Argyroderma piacentini*
			* Osteopoda
				+ Polyschia
					- Platydontia
						* Archeplatydontia
							+ Archeplatydontidae
								- *unspecified*
									* Archeplatydontinae
										+ *Dendronomus vasquezi*
									* Xenodontia†
										+ Brachiocephalia†
										+ Euxenodontia†
											- Streptotarsi†
											- Archexenodontia†
								- Neoplatydontia
									* Pleuroptera
										+ Archepleuroptera
											- Archepleuropteridae†
												* *Anthonomos qbelocki*†
											- Platyptera
												* *Sphenorhynchus sullivanae*
												* Euplatyptera
												* Dermatopoda
													+ Archedermatopoda
													+ Neodermatopoda
														- Rhabdopoda
															* Colobathristes borchmori
														- Compsopoda
										+ Theroptera†
											- Eutheroptera†
												* *Melanopteryx alexanderi*†
											- Chlamyptera†
												* Hypsirhynchidae†
												* Archechlamyptera†
													+ Temnorhynchidae†
														- *Charcharonyx mackrethi*†
													+ Archechlamypteridae†
									* Neoplatydontidae
										+ Scandopoda
											- *Carpophagus xeni*
											- Archescandopoda
											- Neoscandopoda
												* Pholcoscelida
												* Brachyscelida
										+ Harpactopoda†
											- Euharpactopoda†
											- Tanybrachidae†
												* *Cephalocarcinus elvari*†
							+ Copetarsi†
								- *Potamodyptes andrewi*†
						* Edaphotheria
							+ Leptopoda
								- Archeleptopoda
									* Euleptopoda†
										+ Euleptopodidae†
										+ Neoleptopoda†
											- Hoplopoda†
											- Camptopoda†
												* Eucamptopoda†
												* Sphenocerata†
									* Amblypoda
								- Thylacopoda†
									* Archethylacopoda†
										+ *Pycnothrix dicksoni*†
									* Allobrachidae†
										+ Euallobrachidae†
											- Corythobrachidae†
												* Archecorythobrachidae†
												* Camarabrachidae†
													+ *Cyanolophus mcgyveri*†
											- Archeallobrachidae†
												* Archeallobrachinae†
													+ *Melanothrix oneiropolos*†
												* Ceratobrachidae†
													+ *Thyreocephalus cryarchon*†
										+ Teleobrachidae†
											- *Therizinyx elliotti†*
							+ Eurycheridae
								- Archeurycheridae†
									* Archeurycheirinae†
										+ *Prolestes solysti*†
									* *Teratocheirus*†
										+ *Teratocheuirus philipi*†
								- Lystrocheiridae
									* Lystrocheirinae
										+ *Psammonyx deschaini*
									* Trypanocheiridae
										+ Archetrypanocheiridae†
										+ Rhamphodontia
											- Eurhamphodontia
												* Archeramphodontia
													+ Apodomorpha
													+ Archeramphodontidae
														- Archeramphodontinae
														- Coryphodontia
															* Archecoryphodontia
															* Septentrioformes
																+ Phractoformes
																+ Cryptonychidae
																	- Archecryptonychidae
																	- Neocryptonychidae
																		* Theristobrachidae
																		* Glyphonychidae
																			+ Archeglyphonychidae
																			+ Archonychidae
												* Acrocheiridae
													+ Euacrocheiridae
														- Archeacrocheiridae
														- Neoacrocheiridae
															* Heterognatha
																+ Distropheognatha
																	- Archedistropheognatha
																	- Neodistropheognatha
																		* Hadronychidae
																		* Daptodontia
																			+ Dryptognatha
																			+ Flagellifera
																+ Procaecoformes
																	- Oligopoda
																	- Euprocaecoformes
																		* Euprocaecoformidae
																		* Megantroformes
															* Panhylotheria
																+ Hylotheria
																	- Thaumatotheriidae
																	- Euhylotheria
																		* Gyrinotheria
																		* Euhylotheriidae
																			+ Euhylotheriinae
																			+ Pelecodontidae
																+ Thrinaxorhynchidae
																	- Archethrinaxorhynchidae
																	- Dictyorhynchidae
													+ Apatocheiridae†
											- Oryctocheiridae
					- Dromaeopoda
						* Archedromaepoda†
							+ *Rhomaleopus*†
							+ Archedromaeopodidae†
								- *Dromovenator setnovi*†
						* Onychodontia
							+ Euonychodontia†
								- Euonychodontidae†
									* Ensidontia†
										+ Euensidontia†
										+ Prionodontia†
									* Euonychodontinae†
										+ Archeonychodontidae†
										+ Cryptodontia†
											- *Raptonyx junae*†
											- Tachydontia†
											- Eucryptodontia†
								- Hadrodontia†
							+ Allodontia
								- Euallodontia†
									* Archallodontia†
									* Eriotherinae†
								- Thecopoda
									* Euthecopoda†
										+ *Leucothrix caliburi*†
									* Amphidontia
										+ Archeamphidontia†
										+ Xenopsidae
											- *polylophodon thomasi*
											- Archexenopsidae
												* Archexenopsinae
												* Euxenopsidae
													+ Ankistrobrachidae
													+ Neoxenopsidae
														- Teleopsidae
														- Chelaphora
															* Stenochelaphora
															* Pachychelaphora
											- Stenopsidae
												* File:StenopsidaeEvo.pngArchestenopsidae
												* Neostenopsidae
													+ Peloropsidae
														- Archepeloropsidae
														- Anaxotheriidae
													+ Ceratodontia
														- Archeceratodontia
														- Neoceratodontia
															* Aratrodontia
															* Isodontia
																+ Kophodontidae
																+ Elaphrodontia
																	- Archelaphrodontia
																	- Neoelaphrodontia
																		* Spathodontia
																		* Xyrodontia
				+ Synischia
					- Megalobrachidae†
						* Archemegalobrachia†
							+ Archemegalobrachidae†
							+ Prenobrachidae†
						* Titanopoda†
							+ Procerapoda†
								- Euprocerapoda†
									* *Megaphagus matti*†
								- Stylopoda†
									* *Hybotitan bluenoti*†
							+ Baropoda†
								- Eubaropoda†
									* *Nanopus proximensis*†
									* Eubaropodidae†
								- Pachypoda†
					- Deinognatha
						* Eudeinognatha†
							+ Eudeinognathidae†
								- *Euoplos gulielmi*†
							+ Malleognatha†
						* Odontognatha
							+ Trachygnatha†
								- *Telmarchos krisi*†
							+ Dolichognatha
								- Eudolichognatha
									* Archedolichognatha†
									* Hybognatha
								- Pelagotheria†
									* Actatheria†
										+ *Eurypus geberi*†
									* Thalattotheria†
										+ Isopterygia†
										+ Anisopterygia†
											- *Pontodrakon nicholsi*†

* **Chemophyta**
	+ Archaeophyta
	+ Xenophyta
		- Caulophyta
			* Neocaulophyta
				+ Eucaulophyta
					- Eucaulophytaceae
						* Eucaulophytoideae
						* Nothodendrales†
					- Reptophyta
				+ Brachyphyta
					- Archebrachyphyta
						* Eubrachyphyta
							+ Eubrachyphytaceae
							+ Desmophyta
								- Carnophyta†
								- Chromatophyta
									* Archechromatophyta
										+ Archechromatophytacea
										+ Aphyllophyta
									* Zygophyta
										+ Zygophytacea
											- Zygodendrales
											- Archezygophytacea
										+ Harpactophyta†
						* Tylophyta
					- Cryptophyta
						* Eucryptophyta
						* Pagophyta
			* Necrophyta
		- Xylophyta
			* Euxylophyta
				+ Archexylophyta
					- Archexylophytacaea
					- Coelophyta
				+ Nodophyta
			* Altiphyta†
				+ *Trilobophyllus axidenti*†

 † = Extinct