The museum announced that Dippy, who has graced its cathedral-like central hall for 35 years, will make way for the bones of a blue whale that has been hanging in a different hall since 1938.
"The story of the blue whale reminds us of the scale of our responsibility to the planet," Museum Director Michael Dixon said in a statement.
Dippy is expected to go on tour around the country, but plans to remove it from pride of place in the museum has caused much distress on social media.
"What?! The @NHM_London wants to replace Dippy with some daft whale? Crazy idea," @johnmiller opined on Twitter.
Meanwhile, @wriggy suggested that "Replacing Dippy the dinosaur with a blue whale is the equivalent of replacing the Eiffel Tower with a stack of toilet rolls."
