A straightforward workflow to explore species diversity using the Patagonian lizards of the Diplolaemus genus (Iguania: Leiosauridae) as a study case, with the description of a new species.

Abstract

Disputes over species descriptions, stemming from conceptual disparities and arbitrary species boundaries, are among the primary challenges of modern taxonomy. In this study, we introduce a straightforward workflow, grounded in evolutionary theory, designed to tackle these challenges. We exemplified this approach using Patagonian lizards from the Diplolaemus clade. This workflow involves assigning specimens to putative evolutionary lineages, conducting primary species delimitations, constructing a species tree, comparing lineages for evolutionary independence, and using post-hoc analyses to separate well-supported from ambiguous lineages. This approach aims to establish a reliable foundation for exploring the taxonomic and evolutionary diversity of challenging groups. Applying this workflow to the Diplolaemus clade, we used various analytical methods on genetic (mitochondrial and nuclear markers) and phenotypic data (meristic, linear, and geometric morphometrics). We identified ten lineages with varying degrees of evolutionary independence in a clade where only four species had been described. Among the newly identified lineages, two exhibited low support for evolutionary independence, three showed strong support but had non-conclusive information, and one was recognized and described as a new species. In summary, our hierarchical workflow not only facilitated comprehensive comparisons but also enabled us to draw robust conclusions.