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Check out For Want Of A Nail (alt title: Butterfly Effect). It's pretty much this trope - go back in time, accidentally kill one dinosaur, then return to your own time frame and the world has changed. Look at the list of works to see if anything pops out as it. Check the related pages too.
Azzizzi I can think of two films that might be the one with a drill machine, if you're looking for them. One is At The Earths Core, and the other is The Last Dinosaur.
Wikipedia has a list of time travel stories in works of fiction. Maybe looking through the TV shows and movies might help?
https://en.wikipedia.org/wiki/List_of_time_travel_works_of_fiction
Sorry the wait, I was making sure I followed every lead in the links...
The Last Dinosaur has a premise very like it... but isn't (looking the stills and lacking the time travel stuff)
I looked up the stills of At Earths Core too, wasn't it tough...
In adittion to the wikipedia list, I found another one from other site... But no luck yet...
Any new lead I will follow, thanks!
Edited by Raimar

clues: Dinosaur, Time Travel.
. About 15 years ago (around 2001) I saw a movie on TV, live action, looked like a 60's or 70's film... (the picture was very like "The Time Travelers from 1964). .
About a group of scientists that used a fossilized footprint of a "humanoid lizard", that lived among dinosaurs time, to go to the right time in the past with a time machine. .
There they encounter said "humanoid lizard", and after being attacked by Tyranosaur Rex, they manage to kill it... When they come back to "present", it is an alternate world where the lizard type creature rules the world (it's shown just the lab and a "lizard scientist"), shortly they go back in time again and either stops themselves from killing the Ty Rex or they kill the creature, I'm not sure... .
Anyone?
Edited by Raimar