New fossil material of Chelus (Testudines: Chelidae) from the Middle Miocene of Peru

Cadena E.-A.; Salas-Gismondi R.; Zamora-Vega C.; Flynn J.; Antoine P.-O.; Baby P.; Pérez-García A. · Palaeoworld (2026) · DOI: 10.1016/j.palwor.2026.201135

Resumen

We describe two fossil turtle shells of Chelus colombiana from Middle Miocene vertebrate localities in the Fitzcarrald Arch and Iquitos regions of Peru. One specimen represents one of the most complete fossil shells of the genus, also one of the largest known, measuring 84.6 cm in carapace length and estimated to have weighed approximately 65 kg. Morphological comparisons confirm synchronous consistency with other C. colombiana specimens from Colombia and Brazil, with only minor variation in the gular and extragular scutes. These new records extend the known geographic distribution of C. colombiana to the southwestern margins of the Pebas wetland system and support a broader pattern of body size gigantism among Miocene South American turtles, likely driven by ecological connectivity rather than climatic factors. However, the absence of associated cranial material remains a major obstacle to fully resolving the taxonomy of fossil Chelus, a problem further explored in this study.

Instituciones: Universidad Peruana Cayetano Heredia; Universidad Nacional Mayor de San Marcos