Emydidae, Rafinesque, 1815

Páez, Vivian P., Bock, Brian C., Alzate-Estrada, Diego A., Barrientos-Muñoz, Karla G., Cartagena-Otálvaro, Viviana M., Echeverry-Alcendra, Andrea, Gómez-Rincón, Marley T., Ramírez-Gallego, Cristian, Sofía, Jennifer & Vallejo-Betancur, Margarita M., 2022, Turtles of Colombia: an annotated analysis of their diversity, distribution, and conservation status, Amphibian & Reptile Conservation (e 306) 16 (1), pp. 106-135 : 117

Emydidae

Slider turtles. The slider turtles in the Atrato River drainage and the Gulf of Urabá region in northwestern Colombia have long been recognized as morphologically distinct from the slider turtles from other more eastern populations in Colombia, located along the Caribbean coast and in the Sinú, Magdalena, and the lower Cauca river drainages ( Williams 1956; Medem 1958). Medem (1962) and Ceballos-Fonseca and Brand (2014) summarized the details of these morphological differences which involve plastron and color pattern characteristics. However, over the past two decades, the taxonomy of both “western” and “eastern” Colombian slider taxa has been unstable (as has the taxonomy of slider turtles in the Americas overall). The names assigned to the more widespread eastern slider turtle taxon in Colombia include Pseudemys scripta ornata ( Williams 1956) , Pseudemys scripta callirostris ( Moll and Legler 1971; Pritchard and Trebbau 1984), Trachemys callirostris ( Seidel 2002) , and Trachemys venusta callirostris ( Fritz et al. 2012; Parham et al. 2015). Similarly, the names employed for the western Colombian slider turtle taxon include Pseudemys scripta ornata ( Williams 1956) , Pseudemys scripta venusta ( Moll and Legler 1971) , Pseudemys scripta ca. venusta ( Pritchard and Trebbau 1984) , Trachemys venusta ( Seidel 2002) , Trachemys venusta uhrigi ( McCord et al. 2010) , and Trachemys medemi ( Vargas-Ramírez et al. 2017) .

Studies on the relationships of these two taxa to other slider turtle species and subspecies, as well as phylogeographic studies of their origins, have also been equivocal. Over the past two decades, various cladistic analyses have concluded that the two slider turtle taxa in Colombia are either closely ( Stephens and Weins 2003) or distantly ( Seidel 2002) related, and are of Mesoamerican ( Jackson et al. 2008; Fritz et al. 2012) or Caribbean ( Stephens and Weins 2003) origin, or both ( Seidel 2002). Most recently, Vargas-Ramírez et al. (2017) expanded upon the study by Fritz et al. (2012) by adding samples from 12 individuals of the western Colombian slider turtle to their genetic analysis of mtDNA and nuclear DNA. They concluded that South America has been colonized twice by slider turtles from Central America; first by the ancestor of Trachemys dorbigni (currently occurring in Brazil, Uruguay, and Argentina) and the western Colombian slider, which they elevated to the species level, assigning the name Trachemys medemi . Much later, Colombia was again colonized from Central America by the ancestor of the eastern Colombian slider ( Trachemys venusta callirostris ) and the Venezuelan slider ( Trachemys venusta chichiriviche ).