Psephochelys

Psephochelys is an extinct genus of turtle that lived during the Triassic period. Fossils of Psephochelys have been discovered in South Africa. The genus is known from a single species, Psephochelys mirabilis. The name Psephochelys derives from Greek words meaning "pebble turtle," likely referring to the appearance of its shell.

This ancient turtle is significant because it represents one of the earliest known members of the Chelonii, the group that includes all modern turtles and tortoises. Psephochelys exhibits a mosaic of primitive and derived turtle-like features. Its shell, while showing some turtle characteristics, was not fully developed in the way seen in later species, suggesting an intermediate stage in turtle evolution. The carapace was relatively flat and lacked the domed structure of many modern turtles.

The discovery of Psephochelys has provided valuable insights into the early evolutionary history of turtles, helping scientists understand how the characteristic shell of turtles developed over time. It helps fill gaps in the fossil record and sheds light on the diversification of reptiles during the Mesozoic Era. Analysis of its skeletal structure indicates it was likely a terrestrial or semi-aquatic animal.