The song received generally positive reviews from music critics, who noted its stark difference to the other tracks on the EP.
[4][5] During a live performance of "Stoneage Dinosaurs", the backing tape slowed down, making the band sound out of tune.
[7] A melancholy song,[4] "Stoneage Dinosaurs" features "violins, saxophones and funeral paced drums" according to Melody Maker's Mick Mercer.
Mercer wrote that "'Stoneage Dinosaurs' sounds like a sixties dollop", describing it as an "impressively restrained operation" but criticised its length.
[10] He recalled its live performance being "a majestic epic that sent us all home with warm hearts and fuzzy tummies" and "the kind of song that brings everybody down to a nice relaxed high after the frenzied activity of all that's gone before.
[9] In The Independent, Paul T Horgan described the song as sounding different from the other tracks on the EP, calling it a "powerful adagio of lament" and "grossly under-appreciated.