PVSJ 1080 was discovered in a horizon of reddish muddy sandstone just 30 m below the top of the formation, beneath the unconformably overlying Cretaceous aged El Gigante Group.

[2] The margins of the dentary slope inwards to form a sharp keel along the bottom, giving the jaw a sub-triangular cross-section roughly two times as deep as it is wide.

Such bowl-like depressions are unknown in other pterosaurs, and although comparable to similar "cup-shaped" structures reported in Raeticodactylus and Caviramus, differ in their size, position and orientation.

From the partially preserved tooth crown, the teeth are estimated to be slightly backward-curving spikes roughly five times taller than their base width, similar to the condition of various rhamphorhynchid pterosaurs (e.g. Rhamphorhynchus, Angustinaripterus).

[4] This analysis recovered Pachagnathus as a member of Raeticodactylidae, but could not resolve its relationships to Raeticodactylus and Yelaphomte beyond a polytomy of the three species due to a lack of overlapping material.

Notably, in this analysis Pachagnathus was recovered most parsimoniously two times in a much more derived position closer to rhamphorhynchids, raising the possibility it is one of the earliest members of this clade.

[2] Pachagnathus lived in a continental environment a long distance from the nearest coast, and was therefore almost certainly a terrestrial animal, compared to the various coastal Triassic pterosaurs found in the northern hemisphere.