A museum has discovered 150-year-old specimens of platypus and echidna, which are significant because they relate to a 19th-century debate about evolution. These specimens were previously missing and had been stored in a museum, and their discovery has shed light on why some naturalists at the time were skeptical of the platypus. The details of the discovery and its implications are being reported, although some outlets are drawing unrelated parallels with the platypus.