Magnasauria

Magnasauria (meaning "Great lizards") is a clade of ectothermic advanced snakes known commonly as magnasaurs. The first proteromagnasaurs appeared in the Late Primucene period where their ancestors slithered up to land and evolved a second pair of limbs as a result. This clade includes about four modern groups, the arboreal viverrisaurs (Viverrosauria), the fossorial molezards (Talpophioidea), the terrestrial zarpents (Maniphioidea), and the fully aquatic sea dragons (Mosasaurophioidea). Although the word "serpents" is used to refer all members of this clade, magnasaurs are a more vernacular term to describe the members of this group.

Magnasaurs are endemic to many locations in the terraformed exoplanet Chaoterra, but most species of sea dragons live in the Atlas Ocean. Their diets vary by species, many herbivorous species feed on plants, fruits, tree nuts, seeds, and grass; carnivorous species eat fish, mammals, and sauramphastids while others are omnivorous generalists. In terms of cladistics, magnasaurs are the only living descendants of the fully aquatic krayt serpent. The earliest ancestors of the proteromagnasaurs were hesperophid snakes, a group that included the hypercarnivorous Tyrannophis.

Description
The basic body type of the magnasaurs are quadrupedal, though quite a few are bipedal, species who are bipedal walk by pushing their hind limbs forward and their fore limbs backwards. Magnasaurs that are aquatic use their hind limbs (or flipper) as a paddle, while arboreal magnasaurs use their strong fore limbs. Magnasaurs range in size from the small meat scrapper (the smallest mosasaurophioidean) to the massive elerpent, the largest maniphioidean. Magnasaurs could reproduce in many ways, but most of which are oviparous, though many species of sea dragons are ovoviviparous, meaning that they carry their eggs inside their body until they hatch.

Ectothermy
All magnasaurs (excluding the Pumagnus) are ectothermic (meaning "cold-blooded") reptilians. Because of this, they do not have to worry about food energy and will only rely on heat to regulate its body temperature. Some species like the sailback zarpent uses its sail as a solar panel to collect heat to regulate temperature and for intimidation and display. Others such as the basking dragon bask in the heat of the star Prion, hence it's name.

Terrestrial
Roughly 20% of all terrestrial species are plantigrade walkers, using the soles of their feet for locomotion. Maniphioideans are digitigrade, with some being unguligrades, those that are digitigrade walk on their toes, and those that are unguligrade walk by their developed hoofs. Some species are bipedal, using only two limbs for locomotion, species that are bipedal are usually chlamydophids and paradactyls. Bipedal species have a larger field of vision than quadrupeds, conserve more energy and have the ability to grab on to objects with their hands, which helps in foraging.

Arboreal


Arboreal magnasaurs frequently have longer fore limbs than hind limbs (such as the cobrape shown above) that help them cross gaps, reach food sources, and to brachiate (swing between trees). Some species such as the chameleon zarpent use their prehensile tails and opposable thumbs (a feature that was evolved independently) to grasp tree branches. The fastest arboreal species is the gibbon zarpent, which combines opposable thumbs, strong arms, and flexible body to help it maneuver quickly through trees, their thumbs have scales that curve down and could latch on to any surface, even those that are impossible to climb. This is what allows them to climb tree trunks that are so large and are essentially flat from the perspective of a medium-sized animal. However, such scales are easily abused by soft tree skins as they easily get ripped apart, and is highly risky to climb on. Squirpents, instead of relying on opposable thumbs, have sharp claws that can be used to interact with rough substrates and reorient the direction of forces the animal applies. This is what allows the squirpent to climb tree skins that are soft and are essentially risky to climb on by the gibbon zarpent. Claws can interfere with an animal's ability to grasp very small branches however, as they may wrap up too far and puncture the animal's own feet. To control this risk, squirpents evolved highly mobile ankle joints that tolerate the foot rotating into a "reversed" posture. This allows the claws to hook into the rough surface of the bark, opposing the force of gravity.

Aerial
Only one group of magnasaurs (the dracophids) are capable of flight, this is due to the large amount of predators that could compete with it. They have a special membrane called a patagium, these are supported by its unusually elongated ribs and allow them to glide.

Fossorial and Subterranean
Fossorial animals are those that are adapted for digging and lives primarily, but not solely, underground. Examples such as prairie molezards, common molezards, and ground zarpents are one of the fossorial magnasaurs. Many of the talpophioideans are subterranean however. Those that are subterranean spend all their time underground where they live. Usually, those that are fossorial rely on burrows to avoid predators and for food storage, while others are fossorial to aid temperature regulation.

Fossorial magnasaurs usually have stout bodies, and have large shoulders with long slender tails and large claws. As they are unable to see in their dark burrows, nearly all of them have small eyes, with the exception of the prairie molezard, which have large eyes in comparison with its body weight, which averages around 2.2 kg (4.8 lbs). In the case of the common molezard, they have very small, but still functional eyes, only relying on its impeccable sense of smell; ground zarpents have no eyes whatsoever however, as they only rely on their incredible sense of touch. Ground zarpents have remarkably sensitive hands, with five long, tapered fingers and long nails. They lack thumbs, so can’t grasp objects with one hand the way we can, but they use both forepaws together to lift and then acutely manipulate objects, which aids in digging, or picking food.



Aquatic
The Mosasaurophioideans (sea dragons), fully aquatic magnasaurs, were actually the earliest descendant of their ancestors that stayed in the water and gradually developed flippers and a vestigial tail fluke. Sea dragons, like the crocodiles (which are still in chaoterra), are carangiform swimmers, using their tail flukes and body to swim side to side, propelling themselves by swinging their tails while the flippers are tucked to the side while swimming, making it faster. Some species have dorsal fins to stabilize the animal against rolling and to assist in sudden turns.

Semi-aquatic species such as the otter snakes have specialized flippers that help it walk on land, these flippers are also highly mobile and could tolerate crashing into something while swimming. Otter snakes also have several adaptations to reduce drag. Apart from their long, streamlined bodies, they have a network of light-yet-strong scales that are also flexible and makes it easier for the otter snake to slip through water. Otter snakes rely on their longer hind "limbs" for locomotion by propelling themselves in a similar manner to otters, hence its name. Other semi-aquatic species include giant fisnakes, crocophids, and the humpback zarpent. Crocophids are very large semi-aquatic reptiles, and their streamlined body have specialized skeletal structures to bear its massive weight, and have strong flattened tail used as a propeller that allows them to sink and move along the bottom of a river.