What is "podocnemididae"

Podocnemididae is a family of pleurodire turtles native to Madagascar and northern South America. Podocnemidid turtles are commonly called " side-necked turtles" in direct reference to their inability to retract their heads backwards, but hide them sideways. These turtles are all aquatic, inhabiting streams and other flowing water. Their shells are streamlined to aid in swimming.