[4] The bikini raised Welch's stature as a leading sex symbol of the era,[5] and the photograph became something of a cultural phenomenon as a best-selling pinup picture.

The photo taken by Terry O'Neill was deemed too scandalous and was suppressed, until it was published thirty years later by The Sunday Times Magazine.

[13] Hammer originally offered the role of Loana Shell, Welch's character, to Ursula Andress, who four years earlier became a sensation rising out of the sea in a white bikini in Dr. No, the first Bond movie.

[14][15][16] When Andress passed on the project due to commitments and salary demands, a search for a replacement resulted in the selection of Welch.

[17] Welch, who had finished doing Fantastic Voyage under a contract with 20th Century Fox and was touted as America's Ursula Andress,[18] was loaned out to Hammer Studios in Britain.

"[26] One author said, "Although she had only three lines in the film, her luscious figure in a fur bikini made her a star and the dream girl of millions of young moviegoers".

[29] According to Filmfacts, Million Years gave rise to "the familiar quota of buxom starlets about to pop out of their animal skin bikinis, an awful lot of bleached hair" in films with a prehistoric setting.

[30] Hammer Studios tried to re-emulate the fur bikini in Slave Girls (1967) with Welch's Million Years co-star Martine Beswick, When Dinosaurs Ruled the Earth (1970) with Victoria Vetri, and Creatures the World Forgot (1971) with Julie Ege.