The yellow-spotted Amazon river turtle (Podocnemis unifilis), also known commonly as the yellow-headed sideneck turtle and the yellow-spotted river turtle, is one of the largest South American river turtles. It can grow up to 45 cm long and weigh up to 8 kg. This species can be recognized by its black or brown oval carapace (upper shell) with distinctive low keels on the second and third scutes. Yellow spots on the side of its head give this species its common name. These spots are most prominent in juveniles and fade with age. Females can be up to twice the size of males.