What can my sci-fi story be about?

[Coralie]

I already got a brilliant idea but it just seems kliche in a weird way.
Ok, i got two names that are going to appear in the story: Coralie and Nepthalie.
The story is funny nough sci-fi and dinosaurs, prehistoric animals etc never went extinct. So like ammonites, liopleurodon and all those crappy predators living in the ocean is there. So when people go to the beach there's like a 'beware of ammonites' sign there or something. You fly by those dinosaur like reptiles if you wanna go somewhere. Instead of cars there's dinosaurs and you eat them, kill them to fur them (well the world is cruel, you know what i mean). So everything is dinosaur-like but we still got like skyscrapers and hi tech stuff. So what could my story be about?
I got some ideas where a mad scientist tries to overpopulate the sea with predators like liopleurodon, cryptoclidus, giant squids etc. or something like Coralie has a twin sister who died in a dinosaur transportation crash and she got the pov and there's like this creepy dinosaur religion oooohhh. or like there's a machine that takes you to our world where there's no dinos and well.
I want all ideas. even the idiotic ones.
No ALIENS or astronomic stuff! Nothing about paranormal stuff. it has to be about dinos, cuz it's what the story's about.

 

[Fred]

Aliens come from Mars to kill us all. Some guy saves his two kids, who came to visit from their mum; a teenage boy who hates him and a small girl who is too young to understand. The aliens go in massive two-legged mechanisms that fire plasmas to literally disintegrate whom they hit. After 2 hours of (film time) constant running, they find them. They're invisible. Then, they all die; they're allergic to air.

I know: it's called 'The bore of the turds'

 

[Desirae1]

It is discovered by main character, her friend/sister who was missing mysteriously for the longest time, turned up with people after her. It turns out she had ben experimented on against her will, and the religious/scientist are trying to splice and combine human dna with dinosaur dna, as the next step in evolution. They basically want to create a new race of dinapeople. And eventually bomb the earth with a special bio-weapon-gas that will kill all humans and some mammals, and only the dino people will survive and rule the earth. There are many verities of mutant experiments, including dinosaurs with human intelligence, people who can change forms, people half dino, were-dinos etc.