 Unfortunately, the authors do not provide subspecific identification of their single "P. unicornis" specimen.In any case, they took care to exclude captive hybridization in their choice of samples, as it is frequently known to occur in curassows and would have confounded the analysis.Altogether, what can be said with certainty is that there seems to have been some extent of hybridization between at least one population of the southern helmeted curassow and female razor-billed curassows at the end of the Pliocene.