Phylogenetic identity and population structure of the dwarf caimans Paleosuchus spp. in the Orinoco basin of Colombia and Venezuela: filling gaps.

This article focuses on the phylogeography, genetic diversity, and population structure of the dwarf caiman species Paleosuchus palpebrosus and Paleosuchus trigonatus in the Orinoco River basin of Colombia and Venezuela. Using mitochondrial cytochrome b sequences, the study identified distinct genetic clades in the Orinoco basin for both species, which are genetically differentiated from populations in other South American hydrographic basins. The research delineates multiple management units (MUs) for each species—two in Colombia (Orinoco and Amazonas for P. palpebrosus; Orinoco and West Amazon for P. trigonatus) and at least one in Venezuela—highlighting significant genetic structuring and diversity that are critical for conservation planning. The findings emphasize the need to consider these genetic units in conservation strategies due to habitat modification threats and call for expanded geographic sampling to fill remaining knowledge gaps.