There are so many examples of new animal species found through mitochondrial DNA analysis that I believe this should be a routine part of species descriptions. Using morphology alone, taxonomists have often overlooked species that are readily apparent on mitochondrial DNA analysis, including in what should be ideal circumstances using intact adult specimens of large, abundant, and/or economically important organisms. Morphologic characters have been found in some cases but only after DNA has led the way, indicating the discovery process would have been much faster if DNA were analyzed at the beginning. Speed is likely a good way to attract funding, as the public will want the fastest and therefore most economical approach. Mitochondrial DNA analysis can also help extinguish synonomies which have persisted in literature for decades (eg Siddall and Budinoff 2005. Conservation Genetics 6:467).
Under current practice, species recognition whether big or small can be slow (see also earlier post with timeline for discovery of New York Central Park centipede).
Do you see a new species anywhere? Baleen whale specimen collected in 1976, new species description 27 years later based in part on mitochondrial DNA characters (Wada et al. 2003. Nature 426:278)
Does this look like 1904? Honeybee mite Varroa jacobsoni described in 1904. In 1970’s, worldwide epidemic infestation of honeybees presumed due to V. jacobsoni began in Asia. 30 years later, epidemic discovered to be due to a new species, V. destructor (Anderson and Trueman 2000. Exp Appl Acarology 24:165). Species description based on mitochondrial DNA divergence; no morphologic characters other than body size.