Lacertocyon plumocrista

### License
CC0 1.0 Universal Kaelygon 2024
This speculative species is public domain. You must change the original name in the license if you release any variants to avoid misattribution.

---

# Lacertocyon plumocrista

---

## Summary

**Lacertocyon plumocrista** (*feather crested lizard dog*), also known as *feather maned dragon* or simply *maned dragon*.
Despite the name and similarities to reptiles and canines, Lacertocyon belongs to an entirely different family, Lacertherids, that diverged from late Eutherians.

**Temporal range:** Pliocene to present
### Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Lacertheriformes
Family: Lacertheridae
Genus: Lacertocyon
Species: plumocrista

### Traits
- On average: 100 cm tall at withers, weight 45 kg
- Sprint up to 60 km/h, sustained run 30 km/h
- Warm-blooded
- Placental Mammal
- Predator
- Omnivore
- Venomous

---

## Appearance
- Maned dragons are covered in thin fur, and they have a feathered mane that reaches from their head down to the tip of the tail. The mane consists of feather-like keratinous strands evolved from fur.
- This mane can puff up to appear bigger when threatened and acts as a protection and in heat regulation on cold nights.
- Maned dragons have long ears with tufts at the end.
- Their color is a mix of yellows, browns, and greens with lighter countershading. Colorization can also vary depending on the region, mostly due to selective breeding and migrating individuals finding success in certain foliage. Depending on the season, the coloration may vary after shedding the old fur coat.
- Maned dragon's teeth resemble those of canines or raccoons, which are suitable for an omnivorous diet.
- Their whiskers are as wide as their body front profile. When traversing narrow pathways, these whiskers would indicate when the gap is too narrow to fit.
- They have five 3-segmented fingers and four 2-segmented toes, which are closer to reptilian hands than canine paws by appearance. While they are decent at swimming and capable of climbing, the legs and feet are specialized in dense tall foliage and grabbing onto prey.
- Skull shape is similar to reptiles, with external nares positioned like crocodiles. It lacks a rhinarium, but smell receptors are still located in the nasal cavity. The nasal cavity is wet to help with sensing scents.
- Maned dragons have long digitigrade legs to be able to see in tall foliage. Making their gait akin to Maned Wolves.
- The similarities to canines and reptiles are largely superficial. These features evolved convergently to compete with modern carnivora.

### Behavior
- Maned dragons are diurnal. They have trichromatic color vision, which is more advantageous in foraging, but this comes at the cost of poorer night vision.
- Their habitat is dry tropical forest and semiarid desert, and they are most active around temperatures of 10-25 C.
- Maned dragons may share overlapping territories. Despite this, they are rarely aggressive against others unless food is scarce.
- The species is a solitary hunter and can hunt up to 60 kg, but their preferred prey weighs 20-40 kg.
- Though maned dragons aren't the fastest or strongest predator, they rely more on ambushing and stamina.
- Maned dragons are omnivorous and often forage and eat various vegetable matter.
- When food is scarce, they can resort to scavenging. Their stomach acid is strong enough to digest bones.
- Any indigestible material, such as fur or large fragments, is regurgitated in compacted pellets.
- Maned dragons communicate via howls and barks or roars like Maned wolves. When maned dragons are threatened, they can make hissing or growling sounds.

### Reproductive organs
- The reproductive organs of maned dragons are similar to those of some aquatic mammals, such as cetaceans, with a few differences.
- Unlike female cetaceans, which have a mammary slit, L. plumocrista's anus is located outside the urogenital slit, near the root of the tail.
- Both male's and female's sexual organs are internal and the underside is normally featureless.
- In males, the penis and testes are internal, with the penis extending during mating.
- The species has six teats similar to canines, which are hidden under the fur and only become prominent during lactation in nursing females.
- Outside reproductive organs, the species has very little sexual dimorphism.

### Reproduction
- The female gives live birth and nurses a litter of 2 to 6 young with a gestation a period of 3-4 months.
- During this period, the male may share the territory and assist with raising the offspring by hunting and providing protection. They don't necessarily share the same living space until at late stage of the gestation. While the species is mostly solitary, they form some relations between individuals.

### Venom
- Maned dragon has venom glands in the lower jaw. Some of the bottom teeth have grooves for the venom.
- Venom is useful when prey is too large to be disabled quickly by teeth and claws alone, although the venom becomes less effective against anything bigger than 60 kg.
- If the prey becomes troublesome to kill, L. plumocrista may stalk the prey until the venom takes effect.
- The venom may also be used in defense, as it induces intense pain to repel the attacker.

The maned dragon evolved a unique venom composition with effects similar to these components, the actual composition is currently unknown:
- Intense pain: Bradykinin, Capsaicin
- Muscle paralysis: Dendrotoxin, Fasciculins, Conotoxins
- Venom spread promoters: Phospholipases, Metalloproteinases, Vasodilator

---

## Evolution
**Lacertheriformes** diverged from Eutherians before carnivora and convergently evolved alongside them, developing a unique set of traits.
### Lineage
- Amniota
- Cynodontia (259 mya)
- Eutheria (145 mya)
- Palutherium (100-66 mya)
- Palusaurictis (66 mya)
- Lacertherids (34 mya)
- Lacertocyon (5.3 mya)

### Late Cretaceous 100-66 mya
**Genus: Palutherium (Marsh beast)**
- This species diverged during the late Cretaceous period from the Eutheria clade.
- Palutherium was a small semi-aquatic otter/shrew-like insectivores/omnivore.
- Its venom development started early from modified salivary glands. Making the species likely poisonous, if eaten by a predator.
- Like many small mammals, the early ancestors of Lacertocyon were nocturnal to avoid competition with dinosaurs.
### K-Pg extinction 66 mya
- Due to the extinction event, at this stage the species couldn't have been more than 25 kg, likely much smaller.
- Being semi-aquatic provided more shelter, and an omnivorous diet was beneficial, as many plant and marine life died.
### Early paleocene 66-50 mya
**Genus Palusaurictis (Marsh-reptile otter)**
- Many species diversified rapidly after the K-Pg extinction event.
- The ancestral species of Lacertocyon grew in size to fill niches after the extension event.
- As dinosaurs became extinct, the species shifted towards diurnal.
- Other semi-aquatic features evolved further, such as webbed fingers, skull structure, and tail shape, to aid swimming in water.
- As competing species grew in size, Palusaurictis' claws, teeth and venom became more sophisticated. Venom grooves formed in lower teeth.
- This semi-aquatic ancestral species stalked prey in water similar to crocodiles.
### Eocene 50-34 mya
- Proto-Lacertherids shifted from semi-aquatic to more terrestrial due to environmental pressures.
- Development of digitigrade legs, bigger ears, and improved eyesight better suited outside water.
- Better trichromatic color vision to help with foraging, but this comes with a trade-off slightly worse night vision as the species became fully diurnal.
- Outside water, the fur doesn't need to be as dense, but the mane developed to appear bigger in size and puff up when threatened. The fur strands in mane became wider, longer and eventually started to resemble feathers.
### Late Eocene 34 mya to 5.3 mya
- Advanced Lacertherids became fully terrestrial and further adapted to semi-arid and dry tropical environments.
- More competition from other carnivores results in adaptability of diet and behavior.
- As the gestation period lengthened, taking care of offspring became more important.
- Though still mostly solitary, socializing with conspecifics may have become more beneficial to stay competitive with other predators and maintain territories.
### Pliocene 5.3 mya to present
- Modern L. plumocrista emerged from the Lacertheridae lineage.

---

### List of Lacertherids remnant features from their aquatic ancestry
- Venomousness
- Skull, tail shape
- Finger arrangement
- Somewhat dexterous hands and limbs
- Genital slit
- Rib cage flexibility and structure
- Nostrils ability to close when submerged in water
- Nictitating membrane in eye
- Elongated toes and flattened bones in the hands and feet