Well, guess what. I have seen almost every Marvel comic book-themed movie, Avengers, some Wolf guy, (Wolverine, I think?), Iron Man, Captain America, Hulk, plus some Arrow and Flash superhero people.
Do I like them? Nope. Not even a little.
My dd is actively interested (ok, let's be honest, she's obsessed) with all those things. And she doesn't have friends due to her seclusion from being so sick. So I take her to those movies, and she gets a little break from being sick and she loves going and loves that I take her.
I am careful to never tell her that 90% of the time I'm confused. Who's the good guy? Who's the enemy? I always get a basic summary from her on the way to the theater. Ok, so Captain America used to be this guy, and then that happened, so now he's got this power. I enjoy seeing how happy the movies make her, and it helps me relate to her.
You aren't required to like the things your kids develop a passion for. Stop focusing on the "thing" (dinosaurs in this case, Marvel superheros in my case) and focus on the child you have. Ask why your child finds them so interesting. Ask intelligent questions (I get my daughter in a discussion about what super power she wishes she could have, or what real super powers are - such as showing kindness to an unkind person, or being patient under difficult circumstances). You can ask your son about paleontology as a career and an actual science vs just seeing Jurassic Park movies a hundred times. What real science goes into archaeology and paleontology? Egypt just found a new pyramid that's been buried since the 13th century. There's lots to discover.
For you to say you consider paleontology a waste of time to study is pretty condescending. It is an actual field of study. You don't have to be interested in it. You have to demonstrate respect for someone else's interest. Surely you are interested in something: cooking, sewing, your job, computers, floral design, whatever. And surely you realize that not everyone else is interested in the same thing. Don't lie to your son; if he's a functioning young adult, you can tell him that dinosaurs aren't your focus in life, but at least tell him that you appreciate his interest, and you're willing to spend a day with the dinosaurs. And with him.