[1] Odontochelys and Proganochelys share unique primitive features that are not found in Casichelydia, such as tooth-like structures on the pterygoid and vomer and a plate-like coracoid.

[3] Proganochelys was once considered to be the oldest known stem-turtle until the description of Odontochelys and Eorhynchochelys, two slightly earlier genera that lived in the Carnian stage of the Triassic.

Its overall appearance resembled modern turtles in many respects: it lacked teeth on the upper and lower jaw, likely had a beak and had the characteristic heavily armored shell formed from bony plates and ribs which fused together into a solid cage around the internal organs.

Also, unlike any modern species of turtle, its long tail had spikes and terminated in a club, its head could not be retracted under the shell, and its neck may have been protected by small spines.

Although evolution of the shell has been clearly defined, the mechanisms behind the movement of the neck have been a subject of debate for Proganochelys.

It has been hypothesized that Proganochelys were able to retract their necks by tucking in their skull under the front of their shell when needed, perhaps in a similar fashion to some modern side-necked turtles.

[6] The skull of Proganochelys quenstedti from Trossingen, West Germany, retains a number of well-known amniote features not found in any other turtle.

For instance, jaw differentiation, the fusion of the vomer, and the loss of the lacrimal are clear examples of traits that evolved after the evolution of the shell in Proganochelys.

[10] The earliest fossils of Proganochelys were discovered in Germany in the rural towns of Halberstadt, Tübingen, and Trossingen.

[11] Consensus among Geologists placed the fossils in the middle of the Norian, around 210 million years ago, although this is largely an estimate.

[12] The specific ecology of the Late Triassic stem-turtles has been a major point of disagreement for many years among scientists.

Based on morphological data, Proganochelys is believed to have lived in a semi-aquatic environment,[15] though a 2021 study groups it with tortoises and other terrestrial taxa.

[17] Proganochelys belongs to the group Testudinata, which consists of all extant turtles and several taxa of extinct kin.

[18] Odontochelys †Proterochersis †Proganochelys †Palaeochersis †Australochelys †Kayentachelys †Indochelys †Sichuanchelys †Chengyuchelys †Chuannanchelys †Eileanchelys †Heckerochelys †Condorchelys †Naomichelys †Otwayemys †Mongolochelys †Niolamia †Ninjemys †Meiolania †Kallokibotion Testudines (modern turtles) Proganochelys is considered to have lived in the giant continent Laurasia during the Triassic period.