Roughly 14 million years in the future, about 5 million years after a fairly small (8.4 kilometer) asteroid crashed directly into the China-Russia border. This event happened long after humans had left Earth entirely, leaving it a humid, beautiful Eden of life.
What may come as a surprise is the primary inhabitants of the air. While animals still exist, European, Asian, African and Indonesian species took quite the beating. The asteroid and its aftermath wiped out a little over half of all life, primarily ground and air dwelling creatures. Due to the nature of the asteroid, a mixture of rock, hydrogen and frozen oxygen, the plantlife of Earth was left... Relatively unchanged, in reality. While the trees of Eurasia may be totally different from those found today, the land is dominated by huge, branching plants descended from bamboo. Within these interwebbed mega-forests of Eurasia dwell many strange mammals, reptiles and amphibians.
The most prolific of recovering Eurasia's mammalian wildlife is, quite surprisingly, the lesser apes. These creatures are known to us as gibbons, and though they did see a slight downfall in our time, following the huge niches left open by the catastrophe spread out to become some of the most successful animals of the continent. There are no more rhinos, elephants, gorillas, chimps, lions, tigers or well, anything left on Europe/Africa/Asia above the size of a dog. In the wake of the disaster, creatures such as the rodents, mustelids, crustaceans, amphibians, small ungulates and the aforementioned gibbons quickly filled in these niches. Easily the most unique fauna is the descendants of (you guessed it) the gibbons. They have expanded into familiar and... Quite alien niches, most notably are the "skwotch", a huge humanoid creature of the European woodland that stands roughly 9 meters tall. The "baqpaqe" a small, lanky carnivore that latches onto the back of its victims and dispatches them with slashes from strong thumb claws. The "mytre", a human-sized omnivore adapted to the trees. And the immense "prophets", the largest land mammals, let alone primates ever to exist, they are almost solely arboreal, dwelling in the meshed canopy of the gargantuan bamboo forests, they stand a terrifying 9 meters tall that moves as its ancestors did, by swinging from giant branch to giant branch.
Then, there are the Pagours (primavolus orientalis). Large flying descendants of Lar gibbons with a wingspan of 15.4 meters, just a few feet shy of Quetzalcoatlus. It lives on the border of the crater, amongst the newborn mountain range and heavy bamboo forests, it is both a scavenger and active predator, reaching speeds of 240 km/h in straight flight, and breaching the peregrine falcon's top speed of 389 km/h in a dive by getting to an amazing 394 km/h! Making use of the increased oxygen produced by the gargantuan plants allowed its ancestors to increase in size and endurance until they became the kings of the skies. The hunting method of the Pagour is interesting, due to the fact that all of its limbs are flying implements, it must do all handling with its dexterous, beaklike mouth, resulting in a slalom pattern through the forests, chasing down whatever unlucky animal is seen by it first, save for the prophets. After spotting prey, it will relentlessly pursue it until close enough for it to shoot its neck out from its mane and seize the animal in its sharp canines. Terrestrial locomotion, whilst rare, is not impossible. In fact, the Pagour is quite agile on the ground, as it is often found crawling through the mountains in search of a good nesting site for the night.
The only creature that dares confront the Pagour is the nightmarish diablocancerus occisor.