Leptopoda

Polypodia

Sarcopodia

Osteopoda

Polyschia

Platydontia

Edaphotheria

**Leptopoda**

**Leptopoda** (lit. "slender feet") is an order of entirely herbivorous platydonts living in the steppes. Basal Leptopods could reach a high speed to flee predators, like ungulates on Earth.

## Description

A clade of Edaphotheria, Leptopods originally evolved on the steppe, with their diet consisting of brachyphyta. But with the separation of the western and eastern continents and the onset of the ice age, they adapted to live in a wide range of habitats; from Amblypods eking out a living in deserts to Allobrachids that thrived in colder climates. Some clades were the largest Platydonts and among the largest land animals on the planet, second only to the Titanopods, some standing at almost a meter high.

Early in their evolution, Leptopods started out as early Edaphotheres emerging or crawling out onto the Brachyphyte steppe, with their broad teeth already adapted to cope with a diet of mixed foliage, making short work of the Brachyphytes’ soft buds and spongy bulbs. But with a complete lack of cover, they were vulnerable to early predators, like the Deinognathans and steppe-dwelling Dromaeopods like the early Oncychodonts. Luckily, with such an endless amount of food and a high metabolic rate, these herbivorous Edaphotheres were able to invest in speed, undergoing adaptations for cursorial behavior, or running at high speeds. Evolving an erect posture to support long legs with unguligrade hoof-like feet, and a long flexible spine, this made the early Leptopods some of the fastest terrestrial animals for their time, although they were still principal sources of prey to the Onychodonts.

With these adaptations, some of these early Leptopods evolved into specialists as the climate became more cold and dry, caused by the movement of the continents. Two clades of Leptopods evolved to live in these two extremes; the Ambylopods fed exclusively on dry-resistant Tylophytes, further spacing out their legs and developing wider hooves so as to not sink into the sand; Thylacopods, on the other hand, emerged in what was then the tundra of the western half of the supercontinent. to battle the cold, they redeveloped the setae of their Sarcopod ancestors into a long hair like structure, creating a fur-like pelt covering a dense layer of fat. To keep their undeveloped young from freezing to death, they've expanded their sexual gonopods to cradle them close to the females body, giving them a much greater chance of surviving.

But then, when the supercontinent broke apart into two separate landmasses, the once large population of Leptopods had been cut off from on another, leading to large differences in their evolutionary development over the eons.

With the continent being close to the equator, the eastern Leptopods became the Camptopods, becoming more generalistic, feeding not only on brachyphytes but also mixed caulophyte species, necrophytes, and low-lying tree branches. They began to occasionally wander among the strands of trees close to coastal gallery forests, providing a degree of shelter from steppe-dwelling predators. They also congregated in large numbers, as food was abundant enough to keep intraspecific competition to a minimum. And so these Leptopods afforded to evolve collective behaviours for greater safety, forming herds comprising anywhere from several to over a hundred individuals. An exception to this rule were the Sphenoceratans, where males competed aggressively for each other for females, or at least, the females had the final word on who would have the rights to mate.

The western Leptopods however found themselves in a very different continent compared to the east. The dry, ice age climate turned the majority of the continent into desert and arid steppe. Fortunately, their cold-blooded ectothermic predators, like the ancestral Dromaeopods and Deinognathans were unable to regenerate their own body heat to combat the effects of the cold, and so many of them died out and were regulated to the tropics. Even megafaunal animals like the Titanopods were forced into decline, though they were able to maintain their own body temperature thanks to their gigantothermy, this still wasn't enough to deal with the constant oppressive cold and lack of food. On the other hand, Leptopods already had a huge advantage in the new climate, especially the Thylacopods, which, having specialised integument to complement their endothermy, they thrived as other clades were driven to live in warmer environments.

But as they proliferated, they came into contact with the much larger, more robust Hadrodonts and Ensidonts. But with vast stretches of the western continent being largely spare of vegetation for which they couldn't afford to hide, speed and stamina became their primary option. And in the face of competition to evade their new predators, especially the centauristic Onycodonts, a few Thecopods came with one innovate adaptation to abandon the eight-legged gait of most Osteopods by raising their front pair of limbs of the ground - convergently undergoing the same development for similar reasons. With only six legs on the ground at once, these new Thecopods - Allobrachids - ran more efficiently and used their freed-up forelimbs for manipulating them to forage off the tops of Nodophytes: Teleobrachids became specialised for feeding exclusively in this manner.

For millions of years, Allobrachids were the most successful group of herbivorous megafauna on the western continent. With niches left by the Titanopods, they grew considerably larger: not only discouraging predators, but also increasing the amount of body heat they generated, making them more resilient to the cold. In such a demanding and ever-changing landscape, however, their behaviour became more aggressive and competitive. Among the Thylacopods, the burden of females carrying and investing energy on their young made reproduction more costly, casing them to be more selective when it came to mating rights, increasing competition among males, displaying adequate fitness to their offspring.

In one clade, called the Ceratobrachids, The males developed more powerful front forelimbs by growing hardened club-like endings, turning them into powerful punching bags, battering their opponent into submission. To with stand the blows form these confrontations, they also developed reinforced bone on their skull and further armour around their cephalathorax. Another clade of Thylacopods - the Corythobrachids - developed large, vibrant crests with eye-catching colours on their arms and cephalathorax, which males advertised to females without needing to engage in physical confrontation. Despite the fact that their arms at times got in the way of feeding, and were visible to predators, they were maintained purely for the females preference for them.

For a long time, both the Camptopods and Allobrachids expanded and diverged in their respective continents. But although the continents drifted and collided into each other as Allobrachids - in part due to their centurism giving them greater speed and flexibility, with their efficient thermoregulation and reproduction - outcompeted their Camptopod relatives as they moved into the eastern continent, Leptopods as a group were the most adaptable Playtdonts of their age.

After the Mass Extinction, Leptopods were nearly wiped out, with only a few relict species of Amblypod left in the deserts, thanks to their previous adaptations to harsh climates. Unable to recover, their ancestral role as steppe-dwelling herbivores was taken on by their distant relatives, the derived Oligopods: Procaecoform Rhamphodonts.

## Gallery

Thylacopoda compared to Euleptopoda and Amblypoda.Allobrachid in the western contientCamptopod on the eastern continent
## 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