After initial detection of target archival DNA of a 116 year old syntype specimen of the Smooth Lanternshark, Etmopterus pusillus in a single stranded DNA library, we shotgun-sequenced additional 9 million reads from this same DNA library. Sequencing reads were used for extracting mitochondrial sequence information for analyses of mitochondrial DNA characteristics and reconstruction of the mitochondrial genome. The archival DNA is highly fragmented. A total of 4,599 mitochondrial reads were available for the genome reconstruction using an iterative mapping approach. The resulting genome sequence has a 12 times coverage and a length of 16,741 basepairs. All 37 vertebrate mitochondrial loci plus the control region were identified and annotated. The mitochondrial NADH2 gene was subsequently used to place the syntype haplotype in a network comprising multiple E. pusillus samples from various distant localities as well as sequences from a morphological similar species, the Shortfin Smooth Lantern Shark Etmopterus joungi. Results confirm the almost global distribution of E. pusillus and suggest E. joungi to be a junior synonym of E. pusillus. As mitochondrial DNA often represents the only available reference information in non-model organisms, this study illustrates the importance of mitochondrial DNA from an aged, wet-collection type specimen for taxonomy.