Preservation-induced morphological change in salamanders and failed DNA extraction from a decades-old museum specimen: implications for Plethodon ainsworthi

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 preservation artifact. To address this controversy, we tested for morphological changes across five experimental treatments in proxy P. shermani specimens, and we re-examined the datasets used to support the invalidity of P. ainsworthi. We also tested recently developed DNA extraction techniques on the putatively formalin-fixed P. ainsworthi holotype. We used Bayesian models to demonstrate that preservation method can differentially ...