Silvoidea

**Silvoideans** are a clade of ambulospeculids that are alive today.

## Evolution and taxonomy

Silvoideans are a diminished, but ancient group of terrestrial ambulospeculids. They are believed to be extremelly important examples of how ambulospeculids evolved into crescently more terrestrial lifestyles, as seemingly silvoideans are just in between the basal amphibian-egg stage (adopted by bassodids and several basal celestipleures) and the fully terrestrial stage. Silvoideans are fully air-breathers, from hatchling to adult, but they require to lay their eggs in moist soil. This is both caused by a primitive and derived feature in the egg structure, as the egg embryos require extra humidity to develop before hatching out as full air-breathers, and because the eggs of silvoideans are hard-shelled eggs, a noble adaptation for life on land, but one that prevents as much moisture from the outside to be absorbed, forcing these to lay their eggs very close to water, in most cases. Silvoideans are part of the largest and most diverse clade of ambulospeculids: the silvatromouians. The silvatromouians diverged from the celestipleures some 292 million years ago, with a common ancestor that laid eggs in the water. The first silvatromouians originated 290 million years ago, however, not too long after, as more active terrestrial ambulospeculids that were largely capable of laying their eggs outside of the water. Silvatromouians soon divided into two groups, the antecaptorians and the aercampians. Aercampians are the most diverse and abundant, having originated 288 million years ago, already as fully terrestrial creatures, though the first were presumably already active arboreal gliders or even fliers, having evolved extremelly fast after abandoning their ancestral amphibian lifestyle. The antecaptorians first evolved a little bit after, 285 million years ago, as these retained more basal reproductive and morphological features, such as more insectoid bodies and more reliance in water bodies. The basalmost antecaptorians, are the silvoideans, as these are the sister clade to the much wider group of extant antecaptorians: the edurulealians. Edurulealians evolved pretty soon too, 280 million years ago. The first silvoideans are believed to have evolved a bit before, 282 million years ago, with all major extant groups diverging shortly after. Silva spicatas is the basalmost silvoidean, but has evolved extremelly derived features that doesn't make this a reliable analog to the morphology of the first silvoidean. The xenospeculans originated 280 million years, characterized for having well developed legs for walking and supporting their body in the best ways that they can. Vadumspecula is the basalmost xenospeculan, sister to the xenodentians. Xenodentians originated 278 million years ago, as eight legged herbivorous ambulospeculids, though already their two pairs of front limbs were organized close to the front of their body, just as much as the two pairs of back limbs, creating the blue print for fusion of the legs. Presumably, the extant members of this clade, Terebrodente and Xenotitan, evolved limb fusion indpendently, though sharing the same ancestral blueprint that allowed that transition.

Silvatromouia (290-0)

* Antecaptoria (285-0)
	+ Silvoidea (282-0)
		- Silva spicatas
		- Xenospecula (280-0)
			* Vadumspecula spp.
			* Xenodentia (278-0)
				+ Terebrodente
				+ Xenotitan eolania
	+ Edurulealia (280-0)

## Characteristics

   Silvoideans are extremelly odd creatures as a whole, though they have coherent characteristics between each other. For example, their mouth apparatus is consistently composed of three proboscis, to which they feed on. All three proboscis consume the food, though Terebrodente is unique for displaying heteromorph proboscis, in which the central proboscis is sharpened at the end and elongated, twisting itself to work as a drill to perforate through the bone tree bark, where its preferred food lies. Eventually two lateral proboscis are softer and consume the food with more efficiency than the central one, though the central one is still capable of consumption. Xenotitan is the only silvoidean to have relatively short proboscis. This is a characteristic that Xenotitan evolved independently, as it is the only that evolved a low-lying herbivore like stance, which does not require the growth of very large proboscis. Silvoideans have lost the required musculature to retract their proboscis (which might be the reason why they still retain all three of them as feeding organs), so Xenotitan evolved reduced proboscis to avoid typical issues like damaging. Therefore, it lays itself close to the ground to graze on polyspeculates. Vadumspecula has, by far, the longest proboscis of any silvoidean. In fact the largest Vadumspecula species can have proboscis longer than any other non-vadumspeculan silvoidean, reaching astonishing lengths of up to 12 meters! This enormous size is evident, as the creature itself can get titanically massive. These serve as weird mixes between Earth's whales, flamingos and jellyfish, utilizing filter feeding to justify their huge size, achieving terrestriality, walking on soft mud and shallow seas to forage, like a flamingo, and having venomous "filaments" at the tip of each proboscis to filter the food and kill it. Yet again, this is another unique feature among silvoideans. These proboscis are enormous, working in unisson to forage the waters in search of small prey and sessile organisms too (polyspeculates), though relatively large prey can also be consumed, being swallowed down its proboscis. The largest dispeculate a Vadumspecula can feasibly swallow can reach sizes of that of an adult man, implying the surprisingly dangerous nature of this filter feeding behemoth. Silva also has extraordinary repurposings of their proboscis. It possesses three proboscis, and depending on the species, these may include outer barbed spikes, to avoid damage to them or maybe even to keep prey stuck to them, or, in some species, the proboscis are smooth but end in suckers, sticking itself to the prey. The proboscis take the role of keeping the prey still, while it stabs them with the front limbs. The proboscis eventually feed on the prey. Unlike other silvoideans and many dispeculates, the proboscis of Silva seem to stem from the skin, rather than a common branch of three proboscis leading to the central oral orifice. The truth is is that Silva's completely alien cranial morphology forces the proboscis to grow an be directed the same way as the eyes, as the skull bends so that the "nose" points to the ground. Skin grows to cover the location of the oral orifice, as the proboscis grow through the skin, giving the appearance they don't stem from the same place. Olfactory pits in silvoideans have evolved into different arrangements and functions, but basally they retain the same usage and position as in the first ambulospeculids. Vadumspecula and Xenotitan, for instance, retain the basal position. Silva, however, because they have an extremelly odd cranial morphology, have evolved an extremelly odd position for their olfactory pits, surrounding the "eye orb" in a horseshoe-like shape to smell the air in several directions, making these the most scent-sensitive silvoideans. However, unlike Silva, the xenodentians lack advanced scent-sensitive olfactory pits, and instead use their respiratory orifices to sense scent particles while breathing. Xenospeculans as a whole also evolved unique and derived olfactory pits that evolved into sensitive ear holes, an evolutionary technique convergent to, for example, epestredutchiians. This allows them to hear their surroundings, possibly an evolutionary pressure as the first xenospeculans were likely prey creatures. Silvoidean eyes are composed of simple compound eyes, barely different, in terms of structure, from that of the basal ambulospeculid. Most silvoideans have a good sense of vision, with the exception of Terebrodente, whose eyes are diminished, favouring instead scent and audition-based surrounding detection. Silva has one of the most unique eyes, as both compound eyes have merged into a eye orb. As the skull moved down 90º, the eye orb eventually pointed towards the front of the creature, creating extremelly binocular vision, a key trait for many predators. This is in contrast to the largely foraging xenospeculans, many of them being herbivores, subject to predators, so they have eyes positioned at the sides. The internal anatomy of silvoideans respects that of the typical antecaptorians. They have a brain located in their head, with a proper olfactory bulb positioned at the front. A spinal cord runs down the length of the dispeculate, protected by a proper vertebral column, their only proper ossified endoskeletal structure, with their legs being instead supported by cartilaginous and semi-ossified, highly pneumatized, ligaments. The lungs (usually antecaptorian lungs are merged into one communal branching sac, that gives the appearance of a singular lung) are positioned right behind the head and above the stomach. The intestines runs below the stomach. The heart is positioned below the intestines. The kidney, the liver and the reproductive organs are positioned at the back of the body, behind the lungs and the stomach and above the intestines. The kidney is in front of the liver, and the liver in front of the reproductive organs. Silvoideans have a cloaca at the back of their body. During reproduction, they engage in cloacal kisses, but in the case of Vadumspecula, they have an extremelly long fleshy tube that corresponds, in the female, as the ovipositor. The male has a strcuturally identical structure, to pass the sperm to the femal's ovipositor. The somewhat simple lung system of silvoideans and other antecaptorians prevented many from fully procuring highly active terrestrial lifestyles. However, to compensate, several terrestrial antecaptorians, including some silvoideans, have gone around that problem by evolving very complex respiratory orifice networks to increase the air flux and allowing for fast-dwelling activities. But starting with the basal ones. Silva and Vadumspecula retain the simple respiratory orifice structures, composed of simple orifices with lids to allow for water retention. Silva has three pairs of spiracles, just below the front limbs. Vadumspecula has a row of seven pairs of spiracles running down the undersides of the body, starting in the neck, and ending right between the fourth pair of limbs and the ovipositor. Xenodentians, being herbivores, have rapidly evolved their orifices to accomodate more proper air exchange, and allowing for faster movements. This is in contrast to Silva, who is a slow ambush hunter, only making fast bursts to take down prey, and the huge large slow moving foraging Vadumspecula. Terebrodente has seven breathing pairs of spiracles, with three being in front of the front limbs and four being between the front limbs and the back limbs. Xenotitan is unique for having a long horizontal skin notch, between the front and the back limbs, holding the spiracles there, protecting them from moisture loss and gathering of detritus. Additionally, back to Terebrodente, they have four additional spiracles, that are not used for breathing. These are organized as extremelly tall chimnes on their dorso, protected by external armor, that are connected to the respiratory system, to expel air in the form of sounds. These tubes work as their vocalizations, which makes them unique in being the only silvoideans to do that, and the creation of vocalizations is perfectly pressured with their hearing abbilities. Silvoideans, basally, have eight limbs. No silvoidean has lost its limbs, though they have been repurposed for various purposes. One of the most defining characteristics of silvoideans is that they have the developmental ease of being able of merging limbs into one singular limb. Every extant species displays a demonstration of this limb condition, except Vadumspecula. Silva has its two pairs of limbs fused into one functional limb, being fused at the tip by a scythe-like hardened piece of armor. Silva uses this scythe-shaped arms to puncture severe wounds in their prey. The third and four pair of limbs are fleshy and held at the back, being the only ones that support the creature on the ground. Superficially they look like frog feet, though without interdigital membranes. The third pair of limbs has two fleshy fingers, while the fourth has three. Vadumspecula has much more basal-looking limbs, articulated like a typical arthropod. These limbs are extremelly long to allow the creature to walk on soft mud and sand without sinking. At the end, very wide feet composed of cartilaginous rays and membranes around a strong skin pad, can be observed to aid in that effect. All eight limbs support the creature on the ground. Xenodentians, however, perfect the limb fusion teased before. The first xenodentians had limb arrangements that allowed for that condition to form separately in both Terebrodente and Xenotitan, with the first two pairs of limbs being held close together at the front of the body and the two last pairs of limbs being held at the rear. Eventually both lineages merged the limbs into two practical pairs of limbs. Terebrodente has fully merged them into elongated articulated stilt-like legs, that it uses for running. They can run very fast, though they need to conserve their speed, at the risk of breaking a leg. These are the only silvoideans to properly approach a cursorial-like lifestyle, a lifestyle probably common among early xenodentians. Xenotitan, however, has evolved into a more low-lying armored beast, avoiding having to run. It has more basal looking legs, however, with the front and back legs not being fully merged at the base. External integument of silvoideans is mostly composed by smooth skin and hide, a typical skin condition from basal ambulospeculids. They retain a good portion of their external armor, though in many cases, the distribution of said armor plates is reduced to allow for less body weight. Silva has three separate semi-circular armor plates distributed across its back, while most body is naked. The separation of the plates allows for better body flexibility in this species, opposite to xenospeculans. Vadumspecula has extensive head plates reminiscent of the original ambulospeculid condition, touching a row of five dorsal armor plates. These dorsal armor plates cover a relatively smaller area of the body, to diminish weigth. Xenodentians, however, are very armored on their backs, with complex and super intricate armor plates that offer extreme rigidity in the body. This also allows them to receive proper protection against predators. Both Vadumspecula and Xenotitan have a row of thin reddish horns at the back of their head and neck to attract mates, a reminiscent of their common ambulospeculid ancestor.

Silvoideans have wide variations in size, but usually they have chosen to attain titanic sizes. Silva is the smallest. It is a predator, ranging from 35 to 85 cm in length. Xenotitan is a large herbivore, ranging from 3 to 5 meters in length. Terebrodente is shorter, at 2,5 to 2,75 meters in length, but reaching heights of 6 to 6,6 meters. Vadumspecula reaches lengths of between 6 and 8,5 meters, and jawdropping heights of between 10 and 15 meters.

## Distribution and habitat

   Silvoideans have all diverged in the early Tenerian, back when Wallace II was still under the continental rule of the supercontinent. Therefore, all modern branches were already present before the supercontinent started to split. However, their modern distribution is an eventual result of the subsequent faunal turnovers and climatic changes. Silva is found solely on the forests and swamps of Media Insula. Vadumpsecula is found in the coasts of Media Insula and Micha. Terebrodente is found in the mainland forests and shrublands of Auth. Xenotitan is the one whose distribution is much more widespread, though. It is currently found in the temperate and tropical coasts of Virtu, Auth and Media Insula. Although having had origins back in the times of the Tenerian supercontinent, during the Compsogene they have been native to Tenebris, eventually reaching to Media Insula in the late Compsogene, some 75-50 million years ago.

## Diet

Silvoideans have a varied diet, though the most relevant and most common members of the group, are actually grazing herbivores. This was an evolutionary strategy to accomodate their metabolism and anatomy. However, predatory silvoideans do exist, specially the basal ones. Silva is the only fully carnivorous silvoidean. They are small ambush predators. Using sleath to catch prey, they hide in the vegetation, only to jump over a prey, trapping them with their proboscis that hold a strong grip. The creature then uses the long scyte-like arms, to deal proper damage to the prey, letting it succumb, only to consume the prey after. Vadumspecula is the only omnivorous silvoidean. It is a titanic creature, among the tallest dispeculates in Wallace II. However, they are very slow, and stuck to a grazing like lifestyle. They wander around the shallows and in beaches, procuring polyspeculates and small dispeculates to feed on, with their titanic proboscis that hang from their heads. The proboscis end in poisonous tendrils, resembling jellyfish tendrils in terms of function. These will hit small prey, paralizing them, so that the Vadumspecula can later consume. Because Vadumspecula are absolutely titanic, they can swallow prey items as large as an adult man. Xenodentians, however, are fully herbivorous. They evolved mroe cursorial lifestyles, but their stiffened bodies prevent them from relying much on the ambushing flexible movements of predators, like Silva, forcing them to stick with specialized herbivory. Terebrodente feed on small easy to proccess polyspeculate material. Their proboscis are very thin and lack teeth (just like any silvoidean), so they require to feast on soft polyspeculate material. Terebrodente has a long central proboscis, with a sharp straw-like tip, that is used to drill into bone trees, to consume its sap. The proboscis will twist on itself, like a corkscrew, to drill further into the bony exterior. The lateral proboscis will later feed on the material that was recovered from the drilling. Xenotitan is, comparatively, a much more abrasive grazer. It has a short body and short proboscis as a result. Because they can't bend their body, they can only feed on polyspeculates at a certain height, and its not uncommon for Xenotitan to go to flooded areas to feed on aquatic and floating polyspeculate matter. This however, made Xenotitan restricted to swampy areas, and overall, that's what makes xenodentians much less diverse nowadays than they were in the past, as climatic changes restricted their types of lifestyles.

## Behaviour and sociality

Silvoideans don't have much skills in terms of sociality. Most silvoideans are solitary, except during the breeding season. Silva is the most solitary and the most territorial. Outside of the mating season, Silva can engage in cannibalism commonly, defending their hunting territory ferociously. Silva, being ambush hunters, benefit from camouflage, and they actually have the abbility of changing the color of their skin according to the environment, ranging from brown to green. Vadumspecula are also solitary. They graze alone, but they will gather in groups during mating season, however. Terebrodente are solitary as well, only gathering in groups during mating season, migrating to more swampy areas, where their eggs will be laid. They will communicate and display each other through the usage of their large dorsal chimnes, that produce attractive sounds. Xenotitan are, however, the most social of all silvoideans, a characteristic that is benefitial for these herbivores, who procure refuge from predatory attacks. Xenotitan live in small groups, with no hierarchy whatsoever. These can easily dissolve depending on the environmental circumstances, with individuals procuring solitary lifestyles depending on the availability of food and other factors.

## Reproduction

Silvoideans are oviparous, like most ambulospeculids. Their egg structure and embryo development is peculiar however, retaining basal and derived features. The embryo still requires a relevant amount of water exchange with the exterior, but at the same time, silvoidean eggs are hard-shelled eggs. This makes silvoidean eggs, at a first glance, look like ineffective structures. The eggshells are still extremelly porous, and can realized water exchange with more effectiveness than other hard-shelled laying terrestrial dispeculates. This forces silvoideans, however, to lay their eggs in moist environments, close to water, like in moist sand or even mud. It is unknown exactly why they evolved this antithetical egg structure, though hard shells are obviously used to retain more water inside the egg and protect it from predators, as silvoideans don't take care of their young. Silva, during the mating season, are generally cautious. They lift their large arms as both a warning and as a form of sexual display. The male and the female will circle each other, facing each other and examining each other's traits and movements. Once the male and female are convinced of the mating intentions of each other, they proceed to mate. They mate rear to rear, via a simple cloacal kiss. Cloacas in silvoideans are generally mobile, composed by a small nipple-like structure that bends around and moves to reach to a certain position, a strategy that makes them reproductively more effective. Once Silva are done mating, they part ways, and the female proceeds to lay a few hard-shelled eggs in the mud or soft sand. Silva is a bit more derived than xenospeculans: their eggs don't require just as much water exchange, so they have the freedom to lay them even far away from water bodies, as long as it is not too dry. Silva will break the eggshell, when they hatch, with their arms, and will be born fully prepared for life on their own, for the rest of their lives. Vadumspecula engage in less wary sexual rituals. Males and female both posses a crest of thin reddish keratinous horns that they use to display. Once the display is successful they proceed to mate. Vadumpsecula have the most advanced cloacas of all silvoideans, composed by an extremelly elongated muscular tube, that ends in a starfish-esque end. This transports waste, but is also used for reproduction. The male and the female join both of these elongated cloacas and engage in intercourse, a strategy extremelly simple for such titanic beasts. Once the female is ready to lay her eggs, she lays them through the elongated cloaca that now works as a ovipositor. Now she can lay her eggs safely in the ground, without having to bend down to do it, something Vadumspecula have anatomical difficulties in pursuing. The eggs of Vadumspecula are enormous, rivaling or surpassing, in size, of the eggs of any known tetrapod. The eggs are laid in the beach, and the young will be born independent and living on their own. Because the eggs are so massive, Vadumspecula egg shells tend to become more flaky when close to the day of hatching, allowing for the eggshell to be broken with more ease. Terebrodente's sexual display is composed of vocalizations mostly, as they have a comparatively weak sense of vision. The female follows the male in a "song contest" as they are seduced by each other. The mating is done rear to rear. Females don't have the enlarged ovipositor of Vadumpsecula, and so they need to lay down to lay their eggs, something they have less trouble doing, due to the intense flexibility of their legs. They usually lay their eggs in fluvial beaches, and then abandon them to their fate. The young are later born completely independent. Xenotitan use their rows of reddish keratinous structures in their back to attract mates. Once the mating is sucessful they engage in rear to rear copulation. The female will then move to a portion of land that receives proper moisture, where she can lay her eggs. Just like Terebrodente, she has to sit down to lay the eggs. She abandons them, leaving the young to live on their own.