As Moonwatcher, the man-ape who discovers the bone in “The Dawn of Man,” the opening act of Stanley Kubrick’s seminal 2001: A Space Odyssey, Dan Richter was at the center of one of the most influential and important sequences in film history. But he was more than an actor; Richter, who had been working as a mime when he was tapped by Kubrick, actually choreographed the “Dawn of Man” sequence, and worked with the director for two years on the sci-fi epic, which has a special screening at the Tribeca Film Festival this Sunday. (Richter has written about his experiences working on the film in Moonwatcher’s Memoir: A Diary of 2001: A Space Odyssey .) He spoke to Vulture about how he got the part, how they came up with the film’s infamous bone scenes, plus his unlikely friendship with John Lennon and Yoko Ono.

So, how did you get the part of Moonwatcher?

Stanley had shot most of the picture already. They were trying to figure out how to do the opening scenes. They had done tests on dancers, actors — even comedians. He and Arthur C. Clarke were talking about it, and they said, “You know, we haven’t talked to a mime.” It so happened I was teaching private classes in mime in London at the time. Anyway, I was asked if I would go out and let Stanley pick my brain. I said, “If you give me twenty minutes, a stage, leotards, and some towels, I can show you how to do it.” So he hired me to choreograph it, and eventually talked me into playing the part of Moonwatcher as well. I always thought of myself as a choreographer on that film. But I saw it again the other day, and I realized I starred in the thing!

Were the other performers who played the man-apes also mimes?

In England, at that time, there were only two or three mimes at that level. You really needed to be very, very skinny to do this, because of the padding of the costume. We looked at tens of thousands of people. Once we got everybody together, it turned into Parris Island. I had to make them forget everything they had been trained to do and retrain them — break them and rebuild them. I also had to build up their stamina, because it was going to be really difficult to do all that movement in that costume, on a set where the temperature was over 100 degrees.

Kubrick was very fond of research. Did you do a lot of research into ape behavior, too?

That may have been the hardest part. I spent a lot of time at the zoo, in front of the chimp cage and the gorillas. I got all the footage of Jane Goodall’s work and watched it over and over again. I met with anthropologists. My goal was to take this group of twenty man-apes, drop them in a parking lot without telling them what to do, and they would just look right. We even put milk bladders in the female apes’ breasts, because we had two real baby chimps, and we hoped that they would actually drink from the breasts. But they never did.

All this led to one of the greatest Oscar disses in history, where Planet of the Apes was given an Honorary Oscar for Best Makeup, and Stuart Freeborn’s makeup for 2001 was completely overlooked.

It’s very hard for me to comment on that, because I see everything — I see the seams in the costumes that aren’t quite right, all the mistakes. But we did nail the behavior. And … come on! Planet of the Apes? It was so below what we were doing! Also, I’ll tell you something else: We had stuff stolen. I can’t say it was Planet of the Apes, but they were the only other movie shooting at the same time and same place we were. Stanley and I even had someone steal a mask and some ape hands right out from under our noses on the backlot, where someone had hid in a drainage ditch. We were in lockdown all the time.

There are two famous bone scenes in the film: One where you discover the bone as a weapon and the other where you throw the bone up in the air and it cuts to a spaceship. Was all that bone-tossing planned?

Not really. Stanley planned everything in great detail, but he was also the kind of great artist who could capitalize on things when they just happened. I got there and I sort of just dropped a bone down casually, and it hit a rib bone in such a way that it spun up in the air. At first, I said, “I’m sorry, Stanley.” And he said, “No, that’s great.” So, I hit it once, a bone flips, and then I hit it a bit harder, and another bone flips. And it builds and builds, and finally, it all led up to Stanley saying, “Throw the bones in the air!” But that first accidental flipping was what gave us the idea.

After 2001, you wound up becoming very close friends with John Lennon and Yoko Ono. How did that happen?

In the sixties, I was traveling the world and I wound up in Tokyo. Through mutual friends, I met Yoko, who was doing conceptual performances there. We became very close friends. She translated some poems of mine to use as part of her performance. Later, when I was in London working for Stanley, she turned up there to do some shows. We got together again, and we had apartments side by side for a couple of years. Then when John started coming around, suddenly I was drawn into their lives. When they got married, they asked me to come out and help with their projects.

You did keep in touch with Arthur C. Clarke over the years. Did you keep in touch with Kubrick?

I lost touch with him after A Clockwork Orange. I had designed an editing table for John and Yoko, because we were shooting concert footage. Stanley had heard about it, and he called and asked if he could borrow the table. And John and Yoko were going off to L.A. to have their heads shrunk, so John said, “Yeah, that’s cool, let Stanley borrow it.” So I spent a day with Stanley, and that was the last time I saw him. Just before he died, I was realizing I had wanted to write about Moonwatcher, so I was hoping to see him again.

You’ve also written a memoir of your years with John and Yoko.

I lived with them for four years during a critical period in their lives, so I thought it would be interesting for people to read. But I don’t have a publisher for it yet. Yoko and I are still sort of sparring over it, and I’m still not satisfied with the version I have, so I’m doing a rewrite on that. —Bilge Ebiri

Dan Richter on Playing the Ape in ‘2001’, Life With John and Yoko