Ambulopteridae

**Ambulopteridae** (meaning **"walking wing"**), also known by their common name the "Legbirbs", are a group of secondarily terrestrial Ornithosmilids that are completely endemic to the micha islands of Media insula. They have completely modified their main wings to become powerful legs. They have become completely bipedal, balancing with their long tails and their winglets. In some groups the tail has been severely reduced, now they only balance using their winglets.

Currently two subfamilies of Ambulopterids are known. The carnivorous, longtailed vernids (macroaurinae) and the mostly herbivorous and in some cases piscivorous, short tailed ornilopes and storkins (microaurinae).

This group of animals is very derived from the original ornithosmilid body plan, and seem to have diverged soon after the first ornithosmilids evolved. Its likely a group of ornithosmilids got stranded on the micha islands and the lack of predators caused them to become secondarily terrestrial, filling the niches that other dispeculates would fill in other parts of the world.

## **Macroaurinae**

   Macroaurines, also commonly called "vernids", are a subfamily of mostly carnivorous, long tailed ambulopterid ornithosmilids. These animals tend to fill the roles of predators on the micha islands. Some like the kiwers, are small animals commonly being just insectivores or eaters of small dispeculates. Others like the archiverns and the coverns, are large around a meter in height, almost obligate carnivores that eat other megafauna on the islands.

Curently Macroaurinae is divided into two tribes:

* **Aquilykini** (coverns)
* **Nychodactilini** (kiwers and archiverns)

### **Aquilykini**

#### **Coverns**

(Aquilykus versicolor), are currently the only members of the **Aquilykini tribe.** They are common predators in many of the islands on the Micha archipelago. They can weigh almost 20kg and are around a meter in height. They have many small individual variations on each of the different islands. This variations tend to just be in overall body size, but it can also change some of their coloration. Even if they don't look like it, they are excellent swimmers, capable of island hopping and living in multiple environments. Preferring open environments such as prairies or plains.

Coverns themselves are commonly called the more basal of the macroaurines. This is due to them still having the ancestral back fin and having their wing finger still with some membrane. This however doesn't mean they are more primitive. These animals along with their relatives the Archieverns, are among the most intelligent species of Ornithosmilids. Both of this animals have extremely good parental care, live in social groups and can have complex vocalizations and scent signals. Coverns are commonly seen as analogues for wolves or canids, thats because of their behavior of living in family groups and being very organized in their livestyle.

They have been seen doing a sort of pack hunting, not coordinated in the same sense that wolves on earth do with strategic plans, but they do seem to be capable of planing where their prey item will go and allowing another individual to ambush and deliver the killer blow. Coverns are pursuit predators, with long legs derived from their ancestral wings. They can run for a long time pursuing their prey until they fall into an ambush or they become tired. They have been seen creating scent trails for them to follow, and their long tails are used in a manner that allows them to communicate with one another. Flashing their flag like tail fluke around to signal other members of the pack.

Coverns don't have an alpha or something of the sorts in their family structures. The individuals generally are related animals that all help each other rear a single young per mother. Mothers have a gestation period of about 3 weeks, before detaching their egg-sack and doing their nesting behavior in communal mounts or nests. The egg-sacks would hatch after 2 months, with 1 or 2 chicks per egg-sack.

    Females tend to stick to their ancestral pack, while males are driven off to find a different pack. Its common for males to have a much more nomadic lifestyle, moving from pack to pack. This is probably a behavior that aids with inbreeding, as the nomadic males are generally welcomed. They come, live a couple of months with the pack, mate with some of the females and move on. This allows the species as a whole to not have as much inbreeding as they would have otherwise.

### **Nychodactilini**

The Nychodactilina tribe has a set of very specific features, that being they lack the back sail of their ancestors, and more importantly, they have adapted their wing finger into a powerful raptorial claw.

#### **Common Kivern**

(Vexilocauda crepuscularis), also known as the common Kiwer, is a common animal that eats small insect like xenopedans and other small dispeculates. These animals can weigh around 4 to 5 kg and are overall very small in stature. This animals have criptic coloration, being mostly beige and brown with multiple stripes.

These animals are known to be great burrowers. Their large raptorial claw seems to be a great tool that aids them at creating their burrows as well as helping in self defense. The animals tend to be crepuscular or nocturnal. Only going out to hunt when theres low light. They rely on their large eyes, their multiple whiskers and their strong sense of smell to move around. They are known to go out and forage in groups of up to 5 individuals. They always keep a weary eye on one another. They signal each other with their long tails, making signals rapidly in case some predator is near. The flag in their tail has many eye like markings, probably just to help with mating displays, but it could also be that the multiple eyes confuse predators as to where the head of the animals is.

They live in monogamous pairs, they mate annually, having a gestation period of around 2 weeks. Both parents would aid in incubating the egg-sack deep in their burrows. The chicks may hatch after 3 or 4 months, by that time they are well developed. The parents don't do much parental care to the chicks, leaving them to fend for themselves after a month. However the animals tend to live in communities, with parents and children living in burrows close to each other.

The animals have been able to spread to many different islands and environments. They seem to prefer drier environments then most of the other birbs. Though they aren't limited to those environments. commonly seen in the forest or jungle floor just catching insects or small dispeculates.

#### **Striped Archieverns**

(Deinodromeus purpurarhynchus), commonly called purple beaked archiverns, or just archiverns, are close relatives of the common kiwer. They can weight as much as 25kg and are a little over a meter in height. They have converged immensely with the Coverns, and in the past they were even classified to be in the same genus, being called "Aquilykus purpurarhynchus". This soon changed as more details of their anatomy have been revealed.

The animals have the signature nychodactiline raptorial claw. These claws seemingly having been modified from their original purpose of excavating and self defense, and now are used to grapple with prey and to scale trees. This change in diet from small insectivore to large carnivore seems to have happened rather quickly, and they still share some of the same behavior the kiwers have.

If the Coverns are analogues to canids, then you could say that Archieverns are analogues to felines. This animals much more solitary in comparison, live in family groups that may only be of 3 or 4 individuals. The parents mate for life, having one or two chicks. They have a similar gestation period as with kiwers of about a month, and the chicks would hatch after 2 months. In difference to their kiwer relatives, they do care a lot for their chicks. With the chicks being incredibly dependent of their parents. A archievern chick my stay with their parents for up to 3 years. Family groups include the parents, the older siblings and the new smaller chicks. Once the older chicks have reached maturity they will be driven away by the parents to start their own territories.

Archieverns do show slight sexual dimorphism, with males having vibrant pink or magenta head crests, and a set of quills right next to their tail fluke. Females usually lack the set of quills and have much darker head crests. Pairs of archieverns guard their territories furiously, they spread their scent through their scent glands on their heads and through their feces that have a strong scent.

The animals are almost exclusive to forested environments, being expert climbers and excellent ambush hunters. Mostly being nocturnal and hunting in pairs, this animals are like the tigers of the micha island forests. Since Coverns and Archieverns prefer very different environments, this has kept them able to coexist in their island environments quite effectively.

## **Microaurinae**

Microaurines seem to have derived into two large niches, the stork like Storkins, and the herbivorous ornilope legbirbs.

They share some traits within the tribe, those being the lack of tail fluke and back fin, and more importantly their very reduced tails. The tails seem to have been reduced in an adaptation to become more agile and do rapid twists. Likely an adaptation for escaping predators.

Now microaurinae can be divided into two tribes:

* Ungulapedini (ornilopes and legbirbs)
* Longicorpini (storkins and kin)

### **Ungulapedini**

Probably the group to have some of the biggest modification to their limbs. Ungulapedines have changed their single walking toe to become a single horse like hoof. Effectively turning them from digitigrades to unguligrades.This adaptation is likely to aid them in speed, these animals are incredibly fast and move around quite gracefully. Almost like a combination between a horse and an ostrich, you can hear the animal's two legged gallops across the plains most species inhabit. Their wing finger, now heavily reduced, its now used like a defensive spur, usually used when predators come near, but its also commonly used in interspecies combat.

#### **Pastel crested Ornilope**

(Struthiohippos ungulapedus) commonly called the common legbirb, or pastel legbirb, is a common species of ungulapedine ornithosmilid across the many islands. This animal is *the first Ambulopterid Ornithosmilid to be ever found on the micha archipelago.* This is because the animals are incredibly numerous, with large herds in the more open areas of the archipelago easily being in the thousands.

This animals can weigh almost 40 to 50kg and are large birbs of over 1 meter in height. They are known to be effective island hoppers, being found in many islands in the archipelago. This has caused them to show many different pelts and individual variations in the different populations. This means that the animals probably have multiple subspecies all around the archipelago, but for now they seemingly are just small different variations on the species.

Legbirbs are grazers and low level browsers, commonly eating mossgrass or leaves from low level bush like plants. This is a niche they can safely exploit since many of the competition they would face on the continent simply isn't found on the islands. The animals are polygamous, changing mates each mating period. They have a long gestating period of around 8 months. They being large birbs means that the females aren't constrained by the long gestating period of the egg-sack.They will detach the eggsack, which would be broken open in a couple of hours at most. The birbs usually have a single chicks, but twins aren't uncommon. They dont do much parental care however, and the chicks would just join the herd as smaller members. The herd as a whole do protect the young ones, but the chicks are able to walk and even feed from their hard mossgrass meals a couple of hours after they hatch from their eggs.

They are common prey of the Coverns (Aquilykus versicolor) and more forest oriented animals tend to fall prey to the Archieverns (Deinodromeus purpurachromas). This shows that even if the birbs share close relationships with one another, they still behave like predator and prey. With the legbirbs and the vernids seemingly being trapped in a predator prey arms race.

*quick fact: legbirbs have been commonly seen attacking and pursuing buttbois, many feed on the sidobosians, but most seem to harass the buttbois just for fun.*

#### **The Rusty and Royal Longnecked Ornilopes**

(Alturhynchus ferrugus) and (Aturhynchus regalis), *likely the biggest birbs to ever exist.* They are large animals that can weight half a ton and can reach heights of over two meters. They are canopy browsers, their long necks aid them at eating the tips of leaves of trees. They have very long proboscis that are stored in a large poach. This are used to quickly bring branches and leaves, masticate them quickly, and then swallow them whole. They have a gizzard like organ, that they fill with stones that they gather to grind more the leaves and branches that they eat. They walk slowly and deliberately. Their winglets now being the main balancer of their big weight.

This animals are effectively without any predators once they reach their maximum sizes. There have been sightings of animals as large as *three meters in height.* They are most vulnerable as chicks, since they take a long time to mature. The animals in general travel in small groups of up to 6 individuals. This groups may contain animals from all ages, from old matriarchs and patriarchs that protect the groups, to small chicks. They have a long gestating period, it may take over a year for the egg-sack to detach from the parent. Once detached the chick would hatch after an hour or so, very well developed and extremely different from the adults.

The chicks have much more in common with the other legbirbs. With long legs, and weigh no more then 10kgs. They are fast and nimble, and are able to fend for themselves since they hatch. The young chicks would keep close to the adults as they slowly begin to grow. It may take a chick over 10 Wallacian years to become the size of an adult.

Adults are very sexually dimorphic, with males of both species having large iridescent crests. The rusty ornilope (A. ferrugus) having a brownish to orange crest, and the royal ornilope (A. regalis) having an almost golden crest. Their crests are covered in many iridescent scales that make them look almost metallic while they move. The females have a less exaggerated version of the crests, still with the same coloration. Males also have a set of quills similar to turkey beards. This are sexual display organs, and females completely lack these. Males don't fight frequently, if a male encounters another male in while trying to impress a female, then it would flash its crest and start a sort of "pushing" with the other male until one of them gets exhausted. The male that doesn't go away gets to stay with the female and may start a group.

A. ferrugus is slightly more slender then A. regalis. This feature likely is the reason why the rusty ornilope is more widespread, able to live in multiple forested islands. The royal ornilope lives deeper in the jungles of the largest island in the micha island archipelago. The species even if they have very few predators, have large spurs to defend themselves. This is why many predators when they see them stay very far. A single kick from one of this birbs likely leads to rupture of bones and if you get hit by the big spur, the injury would be fatal.

### **Longicorpini**

For a long time this animals were in an unclear placing in the whole ambulopterid taxonomic tree. With strange features that may indicate a totally different subfamily. However recently they have been placed next with the ornilopes due to the same feature they have as microaurines, their short tails. Commonly known as "Storkins", this animals seem to have diverged rapidly from their common ancestor with the legbirbs. Now commonly found in warmer rivers and estuaries, they fill the niche of a "terrestrial stork", having long legs to wade quickly through the water, and long curved proboscis to catch fish like dispeculates.

#### **Long-necked Storkin**

(Collumcorpis gracillis), also called the golden backed storkin, is a medium to large birb that can weigh up to 10 kg and is bigger than one meter in height. They are fast runners with their long legs. They commonly eat fish like dispeculates like a regular member of the longicorpini tribe. It manages this fit through what seems to be a long neck, but *actually is a very long part of its torso*.

What seemingly looks like a neck in Ornithosmilids, is the area between the first limb pair and the second limb pair. However what makes longicorpines different to other long necked ornithosmilids, is that their nostrils are all the *way up next to their heads*. This may be a feature to allow much more oxygen to go into the body, but likely is a feature for snorkeling. The animals are excellent swimmers, they keep their heads up out of water while still being able to breathe. Another adaptation they have is the limited webbing remaining in their flight finger. These adaptations letting them swim effectively through islands, allowing the long-necked storkin to be a extremely effective island hopper.

The storkin has very limited sexual dimorphism, both sexes have the large crest for recognition, but males have two sets of "manes" at the base of the leg. This manes of grey feathering grow only during the anual mating season, and the males with the largest manes tend to win more mates. The males compete for females by doing a sort of dance off, with them getting close to the ground, showing their winglets and hissing at each other. The one that doesnt back away gets to be with a group of females. Usually polygamous, males have no role in parental care of the chicks.

They have a shorter gestation period in comparison to other Ornilopes, with only around 4 months. The animals detach their egg-sacks, and commonly are seen creating mounds and nests nearby river banks. The egg-sack would hatch around a week later with small long legged chicks. The chicks need alot of care, staying with the parents for up to a year. Once they mature, they would be driven off by the mothers.

##### **"Big Bertha"**

On the first expeditions to the micha islands, there was a very weird sighting. *People were describing a gigantic long necked storking*. Around 2 meters in height, with two large manes on her legs, a large aberrant female that was nicknamed "big bertha". This animal was sighted multiple times fighting with males for females, and even trying to mate with some females. It was at first thought it was a male until further sightings showed her with an egg-sack. Afterwards, sightings of big bertha have slowly dwindled, and now her whereabouts are completely unknown. Its unknown if this female suffered through some sort of gigantism, or hormonal imbalance that made her that way. Either way she was an interesting case relating to this species of storkin.

## **Island isolation and their high diversity**

Ambulopteridae have been isolated for a long time on the micha islands, now adapting to fulfill niches that birbs otherwise wouldn't be able to get. From tiger like predators, to kiwi like animals, to large elephant bird like canopy browsers. They show the highest diversity in body plans of all the subfamilies. And even then, *not all of its species are fully known.*

There is multiple depictions of many strange and aberrant Ambulopterid ornithosmilids by multiple different artists. From armored ornilope legbirbs adapted to high temperatures, to ray like fishers, to sloth like animals, and *many more animals that are simply not well known*. Its likely many of this animals may be properly described in the future, but for now we only have the sketches of this interesting but extremely mysterious animals.