Oct. 25 (UPI) -- Paul Dano says he's "so in love" with his newborn daughter.
The 34-year-old actor confirmed on Wednesday's episode of The Tonight Show starring Jimmy Fallon that he welcomed a baby girl with his girlfriend, actress Zoe Kazan, eight weeks ago.
"I'm so tired and I'm so in love," Dano told host Jimmy Fallon.
"It's so extreme. Your heart has gone like supernova in one sense," he added. "We landed from London last week and she cried for like 24 straight hours and you just kind of want to walk through a wall. It's crazy."
Dano and Kazan never publicly announced the actress' pregnancy. The couple have been together 11 years and co-starred in Meek's Cutoff, Ruby Sparks and Dano's new movie and directorial debut, Wildlife.
"Paul took one pass, and gave it to me for notes," Kazan told Page Six this month of working with Dano on the film.
"That wasn't a very happy note-giving experience. I said, 'I think for the sake of our relationship, you should just let me rewrite this.' And we traded it back and forth for about three years,'" she said of the process.
Wildlife stars Carey Mulligan and Jake Gyllenhaal, and opened in theaters last week. Dano is also known for starring in the movies Little Miss Sunshine, There Will Be Blood and Love & Mercy.