The keyboardist and guitarist retired from the band in 2006, but returned for an anniversary show late last year.
Lanier co-founded the Long Island group with guitarist Donald "Buck Dharma" Roeser, drummer Albert Bouchard, singer Les Braunstein and bassist Andrew Winters in the late 1960s. Eric Bloom replaced Braunstein as frontman and after several name changes, the band settled on Blue Oyster Cult in 1971 and were signed to Columbia Records by Clive Davis.
He appeared on all fourteen studio albums released by the band, the most recent being 2001's "Curse of the Hidden Mirror." They are perhaps best known for their guitar-driven hits "(Don't Fear) The Reaper," which peaked at No. 12 on the Hot 100 in 1976, and "Burnin' For You," which reached No. 40 in 1981. The group continues to be active with Roeser and Bloom still in the mix.
Bloom eulogized his "great friend" in a statement posted on his Facebook page on Wednesday, lamenting that Lanier's smoking habit had "finally got him."
"I'll miss the guy even though we hadn't spoken in awhile," he wrote. "He was so talented as a musician and a thinker. He read voraciously, all kinds of things, especially comparative religion. We drove for years together, shared rooms in the early days. We partied, laughed, played. All BOC fans and band members will mourn his death. Ultimately smoking finally got to him. He had been hospitalized with C.O.P.D. It was Allen who heard some old college band tapes of mine and suggested I get a shot as the singer in 1968. A lot of great memories, over 40 years worth. Maybe he's playing a tune with Jim Carroll right now."
Lanier is survived by his wife Dory, sister Mary Anne and mother Martha.