For a start, Doc was only knee high to a dinosaur [a little one] and never got much taller due to ingesting a medical potion intended to stunt the growth of the formidable and forever hungry T-Rex. How he was going to administer this potion remained to be seen, but going by the size of T-Rex's fossilised remains, he failed to deliver the dose and Rexy boy's carnivorous rampage continued unabated.
And a giant asteroid got the blame for the extinction of dinosaurs.
As for the man cave carvings, they were all pictures, cos back in the day I couldn't spell. Oh, and if you visit various caves here and there, and see a picture of a man with an eye patch, that's me... cos I couldn't spell. I say various caves because I moved house a bit. The first place I got evicted from. Yeah, the landlord didn't appreciate me drawing on the walls.