Dincă, VladMontagud, SergioTalavera Mor, GerardHernández-Roldán, JuanMunguira, Miguel L.García-Barros, EnriqueHebert, Paul D. N.Vila, Roger2015-08-032015Dincă, Vlad, Sergio Montagud, Gerard Talavera, Juan Hernández-Roldán, Miguel L. Munguira, Enrique García-Barros, Paul D. N. Hebert, and Roger Vila. 2015. “DNA barcode reference library for Iberian butterflies enables a continental-scale preview of potential cryptic diversity.” Scientific Reports 5 (1): 12395. doi:10.1038/srep12395. http://dx.doi.org/10.1038/srep12395.2045-2322http://nrs.harvard.edu/urn-3:HUL.InstRepos:17820747How common are cryptic species - those overlooked because of their morphological similarity? Despite its wide-ranging implications for biology and conservation, the answer remains open to debate. Butterflies constitute the best-studied invertebrates, playing a similar role as birds do in providing models for vertebrate biology. An accurate assessment of cryptic diversity in this emblematic group requires meticulous case-by-case assessments, but a preview to highlight cases of particular interest will help to direct future studies. We present a survey of mitochondrial genetic diversity for the butterfly fauna of the Iberian Peninsula with unprecedented resolution (3502 DNA barcodes for all 228 species), creating a reliable system for DNA-based identification and for the detection of overlooked diversity. After compiling available data for European butterflies (5782 sequences, 299 species), we applied the Generalized Mixed Yule-Coalescent model to explore potential cryptic diversity at a continental scale. The results indicate that 27.7% of these species include from two to four evolutionary significant units (ESUs), suggesting that cryptic biodiversity may be higher than expected for one of the best-studied invertebrate groups and regions. The ESUs represent important units for conservation, models for studies of evolutionary and speciation processes, and sentinels for future research to unveil hidden diversity.en-USJournal Article2015-08-0310.1038/srep12395