From wikipedia:

Turtle fossils of hatchling and nestling size have been documented in the scientific literature.[66] Paleontologists from North Carolina State University have found the fossilized remains of the world's largest turtle in a coal mine in Colombia. The specimen named as Carbonemys cofrinii is around 60 million years old and nearly 2.4 m (8 ft) long.[67]

In 2005, the holotype specimen was discovered in the Cerrejón coal mine by a North Carolina State University doctoral student named Edwin Cadena. It had a shell that measured about 1.72 metres (5 ft 8 in), making it one of the world's largest turtles.[2][3]

The jaws of Carbonemys were massive and would be powerful enough to eat crocodylians, that were abundant in the first neotropical forest of the Cerrejón Formation.[4] This turtle coexisted with the giant boid, Titanoboa.