[1] First described from the Chañares Formation of Argentina by A. S. Romer in 1971, Lagerpeton's anatomy is somewhat incompletely known, with fossil specimens accounting for the pelvic girdle, hindlimbs, posterior presacral, sacral and anterior caudal vertebrae.

MCZ 4121 represents a few vertebrae, a pair of scapulocoracoids (mislabeled as belonging to Lagosuchus) and portions of the hip and hindlimbs, including two complete femurs.

[10] This ichnogenus, named Prorotodactylus shares multiple synapomorphic characters with Lagerpeton including approximately parallel digits II, III and IV, fused metatarsus, digitigrade posture and reduced digits I and V. Prorotodactylus also shares the, previously autapomorphic, Pes (anatomy) morphology of Lagerpeton.

If this ichnogenus represents a close relative of Lagerpeton, it would push back the origin of this taxon to the Early Triassic; as a quadrupedal basal dinosauromorph, it also raises questions debating the theory that bipedalism is ancestral to dinosaurs.

[10] Lagerpeton is the namesake of the family Lagerpetidae, a group of small avemetatarsalians which coexisted alongside dinosaurs for much of the Late Triassic.

[3] The oldest fossils of L. chanarensis were found in the Chañares Formation and originate from the Upper Middle Triassic (Ladinian) of Gondwana, southern Pangaea.

Three morphological characteristics in L. chanarensis fossils have been putatively cited as evidence of saltation in this taxon: inclined neural spines, a small pelvic girdle, and didactyly.

[1] The neural spines of the posterior dorsal vertebrae are inclined anteriorly, a character not observed in any other archosaur, but common in saltatory mammals.

[9] Vertebral adaptations of extant organisms exceed those seen in Lagerpeton; the sacral vertebrae of modern saltators are fused and the neural spines reduced.