Four whales stranded on the coast of California in the 1970s were identified as Hector’s beaked whale Mesoplodon hectori (Mead 1981 J Mammalogy 62:430). 20 years later mitochondrial DNA analysis revealed these 4 specimens, and a fifth stranded in 1997, to be a new species, designated Perrin’s beaked whale Mesoplodon perrini (Dalebout et al 2002 Marine Mammal Sci 18:577). The presence of a new species was first recognized by researchers compiling a database of mitochondrial DNA to assist in species identification. The formal species description includes diagnostic molecular characters, helping integrate DNA sequence data with classical taxonomy. As emphasized by Rob DeSalle and others, there is a need to interweave phylogeny and classical taxonomy, which can be met by including DNA sequences routinely used for evolutionary analysis as diagnostic characters in species descriptions (DeSalle et al. 2005 Phil Trans Royal Soc B 360:1905).
I find it remarkable that a species as large as a whale can languish unrecognized in a collection. How many new species lurk in museum drawers awaiting discovery? A comprehensive DNA barcode survey of a tissue collection could be relatively inexpensive, as DNA isolation from tissues is generally simple and and sequencing costs are approaching a $1 a specimen. If whales can hide in museums for 20 years, there must be a multitude of new species already collected that will be uncovered by DNA analysis.