The back-story: the A. pachypus complex (as the authors refer to it, except using the generic name Norops) has in recent years been split in Panama into four species, but complex member A. tropidolepis remained intact in Costa Rica. These lizards are long-limbed, narrow-padded lizards found near the ground at high elevations.
Based on eight years of collecting, Köhler and colleagues now split the group in Costa Rica into three species that are somewhat genetically differentiated at the 16s mitochondrial gene and that differ in hemipenial morphology and to some extent in scalation. One of the OTUs (operational taxonomic units), comprised of a single individual, has the mtDNA of one species and the hemipenis morphology of another and is interpreted as evidence of hybridization.
The paper includes interesting discussion of bar-coding and how one goes from degree of genetic differentiation to decisions on species delineation.
One highlight of the paper was the icon shown below, which occurred at the bottom of one of the pages at the end of the article without explanation. A quick look at the other two papers in the issue revealed that each has its own logo–nice!