BECAS
CARATELLI Martina
congresos y reuniones científicas
Título:
NEW RECORDS OF VERTEBRATES AND TRACE FOSSILS FROM THE HUINCUL FORMATION (CENOMANIAN-TURONIAN, UPPER CRETACEOUS) IN THE VICINITY OF EL CHOCÓN, NEUQUÉN PROVINCE, ARGENTINA
Autor/es:
CANALE JUAN; GARRIDO ALBERTO; CITTON, PAOLO; DE VALAIS SILVINA; BAIANO MATTINA; PALOMBI DAMIANO; CARATELLI MARTINA; APESTEGUÍA SEBASTIAN; MANIEL I.; FERNANDEZ DUMONT M. L.
Lugar:
Salta
Reunión:
Congreso; REUNIÓN DE COMUNICACIONES DE LA ASOCIACIÓN PALEONTOLÓGICA ARGENTINA; 2022
Institución organizadora:
APA
Resumen:
The Huincul Formation (Neuquén Group) has preserved a rich fauna of continentalfossil vertebrates, biased towards large forms, almost exclusively dinosaurs. Thiscontrasts with the underlying Candeleros Formation, where records of small vertebratesand tracks abound. Here we present new trace and corporeous fossils records from thelower section of the Huincul Formation, outcropping at the Cañadón del Cocodrilo site,about 4 km NE of Villa El Chocón. Sub-circular to ovoidal depressions of decimetricdimension are preserved on the top-surface of reddish, fine- to medium-grainedsandstones. Concave hyporeliefs show mutual alignment and narrow, fairly developedrims bordering their outer edge, suggesting identifying them as dinosaur tracks. A singlekidney-shaped hyporelief, resembling a sauropod manus print in morphology, furthersupports our hypothesis. Invertebrate traces are straight to gently sinuous and variablyoriented, unlined, cylindrical, meniscate backfilled burrows, up to 18 mm wide, withrare secondary branching. Invertebrate traces resemble the ichnospecies Taenidiumbarretti, indicative of the ‘pre-desiccation’ suite of the Scoyenia ichnofacies. Thevertebrate remains collected include part of a hypoplastron (Museo Municipal “ErnestoBachmann” collection: MMCh-PV 302), which on the basis of the ornamentation andthe loose connection of the inguinal pillar between the carapace and the plastron, isreferred to a turtle Chelidae pleurodiran. It is remarkable that the position of theabdominal-femoral sulcus is different to that present in other fossil chelids of theNeuquina Basin. A fragment of a right mandible (MMCh-PV 303) was collected, whosedensely packed acrodont teeth, with a subtriangular section, allow its assignment to asphenodontian lepidosaur Eilenodontinae, cf. Priosphenodon sp. A partial skeleton(MMCh-PV 304) was recovered including an incomplete skull which displays subcircular supratemporal fenestrae and unornamented quadratojugal, that, along withthe small size of the specimen allow to assign it to the crocodyliform NotosuchiaUruguaysuchidae. Some features, such as the narrow dorsal surface of the parietalbetween the supratemporal fenestrae, elevated rims along the margins of these fenestrae,the low medial longitudinal crest over the frontals and angular with and oblique andstrongly marked crest, resemble the species Araripesuchus buitreraensis. This is thefirst record of vertebrate tracks, chelid turtle, and notosuchian crocodyle remains at theHuincul Formation. This assemblage strongly expands the knowledge of the fossil faunafor this geological unit, and helps to fill the record gap of certain groups of vertebratesin the Patagonian Cretaceous.