Sphenocerata

## Taxonomy

Polypodia

Sarcopodia

Neopoda

Osteopoda

Polyschia

Platydontia

Edaphotheria

Leptopoda

Archeleptopoda

Euleptopoda

Camptopoda

**Sphenocerata**

## Description

A clade of sexually dimorphic Camptopods that have evolved a haremic mating system; a typical group consists of 3-20 females and a single dominant male. When two rival males challenge each other for control of the harem. Most of the time the males will seek to avoid injury, so most conflicts simply involve the males stamping their feet and waving their horns at each other from a safe distance as a threat display, as well a producing a deep guttural growl, but if that’s not enough to settle a dispute, they may resort to attacking each other. Unlike the allobrachids, the sphenoceratans are protogynous; if a female judges the dominant male as an unfit mate, then she’ll become male and challenge the dominant male in an attempt to replace him. To maintain control of the group, the dominant male will act aggressively toward females to keep them in line, and if any of them begin to show signs of becoming male, he may drive them out of the group.

## 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