[4] The name honors the prolific paleontologist Eugene S. Gaffney, an authority on the anatomy and phylogeny of turtles in general and meiolaniids in particular.

The species name meanwhile derives from auricle, the external ear, due to the prominent halfmoon-shaped rim that surrounds the tympanic cavity.

This is a huge detriment to research on this taxon, as the cranial scutes are considered to be diagnostic for meiolaniids and distinct for the different species.

The cavity itself is surrounded by a halfmoon-shaped rim formed by the squamosal and quadratojugal, which sets Gaffneylania apart from other meiolaniids.

The B horns differ significantly across the meiolaniid family, being flat and directed to the sides in Niolamia and cow-like in Meiolania.

The forelimbs are short and robust based on the morphology of the humerus, with the authors comparing them to those of Meiolania platyceps, material tentatively referred to Niolamia and the much more basal Proganochelys.

While the forelimbs are known from a complete and one partial humerus, the hindlimbs are only preserved through much more fragmentary material, specifically fragments of a femur and a tibia.

These osteoderms show a great variety in their size and shape, ranging from large teardrop-shaped elements to small disc-shaped bones.

The surface of the individual plates is ornamented by fine foramina and the bones grow thicker towards the outer edge of the shell.

[4] The initial strict consensus tree produced to determine the relationship between Gaffneylania and other meiolaniids suffered from the presence of multiple polytomies.

Despite being regarded as a wildcard taxon and its varying position within the family, it was still determined that Gaffneylania consistently nested within Meiolaniidae.

[4] The reduced strict consensus tree is depicted below, showing the different placements that Gaffneylania might occupy within the family.

[3] Sterli and colleagues propose that meiolaniids, and other turtles, went extinct in Patagonia during the middle Eocene after building pressure from climate change, creating colder and dryer conditions.