CONICET | Buscador de Institutos y Recursos Humanos

The present contribution describes new findings of Triassic footprints from the Cuyo Basin, which belong to the Sierra de Las Peñas depocenter. They were recovered from two localities, quebrada de Las Peñas and Fiochetta quarry, belonging to the middle section of the Cerro de Las Cabras Formation. Previously recorded tracks include Chirotherium barthii, Dicynodontipus ispp., Tetrasauropus isp., cf. Grallator, and cf. Rigalites. The new finding from the first locality is a deeply impressed manus-pes set and a partially preserved footprint belonging to a large quadruped. The hind print is 49 cm long and 33 cm wide showing no clear digit imprints, while the manus impression is 30 cm long and 36 cm wide, with at least three anteriorly directed digit imprints. These tracks were found in mudcracked and finely laminated playa-lake facies. The Fiochetta quarry has yielded numerous well-preserved tracks and trackways, the most abundant are tracks of another large quadruped, showing pentadactyl manus and pes. The manus prints are kidney-shaped and deeper impressed than the pes prints, averaging 22.8 cm long and 32.2 cm wide, while the hind prints are rounded and average 21 cm long and 22.3 cm wide. These footprints are preserved in claystones intercalated with marly siltstones and sandstones showing ripples, desiccation cracks and raindrop imprints, originated in shallow ephemeral lakes and mud-flats. These specimens are comparable with the ichnogenus Pentasauropus Ellenberger. From the same quarry, four smaller footprints display a typical chirotheroid morphology. They are larger than wide, pentadactyl with digits I to IV anteriorly directed and digit V laterally directed. The track assemblage from the Fiochetta quarry is comparable to that of the Portezuelo Formation in the San Juan province and the lower units of the Elliot Formation of South Africa.

enviar mensaje