The early evolution of turtles continues to be a contentious issue in vertebrate palaeontology. Recent reports have suggested that they are diapsids(1-6), but the position of turtles within Diapsida is controversial(7-12) and the sequence of acquisition of turtle synapomorphies remains unclear(1-3). Here we describe a Triassic turtle from China that has a mixture of derived characters and plesiomorphic features. To our knowledge, it represents the earliest known stem turtle with an edentulous beak and a rigid puboischiadic plate. The discovery of this new form reveals a complex early history of turtles.