Novelist Larry McMurtry, who wrote of complex relationships in novels such as "The Last Picture Show" and "Terms of Endearment," and then helped redefine the American Old West with the epic "Lonesome Dove," has died at 84, his publicist said on Friday.

McMurtry died on Thursday night, publicist Amanda Lundberg said. She did not immediately have any further details, including how or where the author died.

In addition to his Pulitzer Prize for "Lonesome Dove" in 1986, McMurtry won an Academy Award in 2006 with writing partner Diana Ossana for the screenplay for "Brokeback Mountain" about the relationship between two gay cowboys. He also was nominated in 1972 for his adaptation of his novel "The Last Picture Show."

McMurtry wrote nearly 50 books - collections of essays and criticism and memoirs in addition to his novels - but "Lonesome Dove" had the most impact. It was a sweeping tale of two aging former Texas Rangers - the amiable Gus and cantankerous Call - on a cattle drive from Texas to Montana.

"If anybody had any sense, they'd throw out 'Moby-Dick' and put 'Lonesome Dove' in the center as the great American epic novel," Carolyn See, a literature professor at the University of California Los Angeles, told the Los Angeles Times in 2003.

"No question about it. His heroes in that book are just terrific. His women are just terrific. And he sustains it for 800 pages."

McMurtry developed lasting affection for many of his characters and quite often brought them back for sequels. The principles from "Lonesome Dove" would eventually be in four books and the characters from "The Last Picture Show" generated five novels.

Critics praised McMurtry for his skill in fashioning nuanced and compelling characters and the way he brought them together - whether they were coming-of-age teenagers fighting small-town ennui in "The Last Picture Show" or a self-absorbed woman and her needy, dying daughter in "Terms of Endearment."

McMurtry had a contrarian streak - he wore jeans over his tuxedo jacket to pick up his Oscar - and took a simple approach to his writing.

"I like making stuff up," he told Texas Monthly in 2016. "I just write."

(Writing and reporting by Cynthia Osterman; Additional reporting by Lisa Richwine and Peter Szekely; Editing by Franklin Paul, Bill Trott and Alistair Bell)