The Crack History of the Universe Book 1 Ch.28 The End of the Prehistoric Age.
After the Reconquest of the Earth that the Dinosaur Empire carried out against its foes the Dinosaur Emperor demanded a Space Force be constructed to begin to conquer the galaxy as mobile suits and anti-spacecraft weaponry alike were deployed and developed under the Dinosaur Empire’s watch.
Increasingly a conspiracy of population control and corralling was enacted on the populace within the Dinosaur Empire as they were increasingly encouraged to move into underground Anti-Armageddon Bunkers buried within the ground for reasons of safety using a campaign prefaced on the “things from outer space” which was extremely effective in moving a small portion of the population into these bunkers.
The Great Impacts
It turns out that the Anti-Armageddon Bunkers were very effective with their intended purpose of sustainable and comfortable living underneath the Earth; if under the absolute monarchy that was the Dinosaur Empire. However, many of these bunkers were still importing food from the outside with very few exceptions becoming entirely self-sufficient underground.
These self-sufficient bunkers would be the last remnants of Dinosaur Civilization when the meteors struck the Earth.
Whether the meteor storm was caused intentionally by invaders or whether it was by sheer unbelievably bad luck. The meteors still came and many many sentients upon the surface of the Earth died. Extinction was realized or inevitable for many species across the Earth.
Reactions to the Impacts
The Guardian Beasts respond to the possible annihilation of their followers and worshippers by making a pocket dimension for humans and Dinosaurs alike to stow away inside of to avoid the nightmarish apocalypse that would be the Meteor Storm! Some Dinosaurs also fled the Earth entirely by hijacking a prototype space colony that they launched and piloted to a new Dinosaur Planet elsewhere in the galaxy!
Meanwhile with the Serpent People they wait out the initial meteor storm and then they plan to emerge from their secret bunkers and hideaways to rebuild their civilization upon the rubble of the old Dinosaur Empire. Ordinarily this would have gone well except for an evolutionary offshoot within the Serpent People that evolved through breeding with human slaves without converting them along with the help of the Dreamstone for their Magic powers they had access to!
In the subsequent Reptite-Serpent Schism the Reptites install their new Queen: Azala as the new Queen of all the Reptites and their new civilization and they beat back the Serpent People into hiding again.
Reptite Civilization
With Queen Azala ruling over the Earth as the undisputed overlord of the planet with her small but rapidly blooming new civilization the Reptites began to expand outward as they annexed surviving pockets of sentients and immediately enslaved them as vassals and other forms of slave labor underneath their might.
One odd documented event that occurred in the Reptite Civilization was a Time Crime committed by Timmy Turner who went back in time to film an action movie; and he summoned the actor: Sylvester Calzone to fight several Dinosaurs for one of his scenes! This consequently significantly weakened the Reptite’s slave labor within their civilization.
The Reptite’s main primary stronghold was the Tyranno Lair which was erected upon a patch of land surrounded by lava and from this point they would carry out their ambitions of a fledgling empire as they killed their ancestors the Serpent People and enslaved or murdered many sentients that fell within their growing reach.
The only ones who dared to oppose them were the Ioka Tribe led by their chieftain Ayla the warrior cavewoman who valiantly gathered the last of humanity into her tribe’s alliance to beat back the Reptite menace before it could grow too powerful to stop!
The Two Fates of the Reptites
The Reptite Civilization was known to be rather technologically advanced if cripplingly weak to electrical shocks. In one parallel universe, it was observed that the Reptites would eventually overtake Humanity and stop their extinction then evolving into the lifeforms known as the Dragonians who would become the dominant species upon the planet Earth and forge a new civilization and create the Dragon Gods biotech based organisms that could manipulate the forces of Earth to their very whims to enhance the Dragonians Civilization and quality of life.
However, in our timeline proper the Dragonians never came to be. As the Iokans under Ayla and later the legendary adventurer Chrono and his many companions had fought the Reptite’s back to their stronghold the Tyranno Lair and as the lair was all but destroyed in the final assault upon it one more blight would make itself known upon the planet Earth as the great alien parasite Lavos landed upon the Tyranno Lair and crushed it completely into ruins!
The World After Lavos
With Lavos’s impact upon the planet it began its long feeding upon the planet Earth’s energies and mana as a living parasite to eventually replicate itself and spread to other worlds by reproducing with more spawns of itself! But for now it laid dormant beneath the Earth within the ruins that were Tyranno Lair feeding and plotting…
Lavos’s impact would mark the beginning of an Ice Age upon the planet Earth as temperatures upon the surface gradually cooled increasingly quickly and the world became quite hostile to all living things upon it…
EDIT:
Sources:
fairlyoddparents.wikia.com/wik…
www.chronowiki.org/wiki/Tyrann…
www.chronowiki.org/wiki/Ioka_V…
www.chronowiki.org/wiki/Dragon…
www.chronowiki.org/wiki/Reptit…
www.chronowiki.org/wiki/Ayla
www.chronowiki.org/wiki/Dragon…
www.chronowiki.org/wiki/Prehis…
www.chronowiki.org/wiki/Lavos