Natural history collections are important data repositories, but different chemical treatments of specimens can influence morphological measurements and DNA extraction, complicating taxonomic and conservation decisions dependent upon these data. One such example is the Bay Springs Salamander (Plethodon ainsworthi), the only United States amphibian categorized as Extinct by the IUCN. Recent research has proposed that P. ainsworthi is an invalid taxon, arguing that the 55-year-old type specimens’ morphological distinctiveness from syntopic P. mississippi is a...