The Mata mata (Chelus fimbriata)

bservations of morphological differences among specimens of mata mata found distinctive differences in the populations of the Amazon and Orinoco basins.[11] A genomic analysis of the mata mata was reported in 2020, which showed a deep split between the populations in the Amazon and Orinoco basins. The authors proposed that the Orinoco population be assigned to a new species, Chelus orinocensis, with the Amazon population retaining the Chelus fimbriatus species designation.