Taxonomy: Sus bucculentus revisited

In 1997, the rediscovery of Sus bucculentus in Laos was announced by Groves et al.--this wild pig species had gone unrecorded since first being described in 1892. Although the identification of the new specimen was based initially on morphology, the authors also used a 7% sequence divergence from the common Eurasian pig S. scrofa (based on their analysis of 327 base pairs of the gene encoding mitochondrial 12S ribosomal RNA) as support for the species status of S. bucculentus. Concerned about the large divergence reported for a relatively conserved gene, and the absence of the sequence in any public database, we analysed an additional tissue sample from the specimen and found only 0.6% divergence from S. scrofa. Our more extensive analysis places the sample within the S. scrofa clade, calling into question the species status of S. bucculentus and demonstrating the need for both phylogenetic and morphological evidence in defining species.