INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Small cynodont footprints from the Middle Triassic Cerro de las Cabras Formation, Mendoza Province, Argentina
KRAPOVICKAS, VERÓNICA; GAETANO, LEANDRO; MANCUSO, ADRIANA CECILIA; MARSICANO, CLAUDIA
Jornada; Jornadas Argentinas de Paleontología de Vertebrados; 2015
Triassic cynodonts from Argentina are known from a relatively abundant corporeal fossil record whereas ichnological evidence is notoriously scarcer. Mesozoic footprints attributable to cynodonts or closely related taxa (eutheriodonts) have been described from a handful of Middle Triassic-Middle Jurassic localities from Argentina (Cerro de Las Cabras Los Rastros, Los Menucos, Portezuelo , and La Matilde formations). We present herein the finding of previously unreported, small, well preserved footprints assignable to cynodonts at Sierra de La Peña area, Mendoza Province, Argentina. The material recorded consists in small isolated manus-pes sets. The footprints are homopod, symmetric, and pentadactil. Digits II-IV are of equal length and anteriorly directed, while digits I and V are slightly shorter and more laterally directed than the central digit impressions. The manus and pes are wider than long (14 x 10 mm), present short metatarsal/carpal impressions, and lack a calcanear impression. The La Peña footprints differ from the Triassic examples in the small size, the symmetry, and the lack of a calcanear impression and are highly comparable with those of Ameghinichnus patagonicus from The Middle Jurassic La Matilde Formation. The autopodial anatomy of known Triassic Argentinean cynodont taxa is poorly documented precluding specific trackmarker identification on the basis of pedal or manual morphological traits. Nevertheless, it can be ascertained that the size of the footprints described here is approximately coincident to what is expected of Andescynodon mendozensis whereas Cromptodon mamiferoides, the only other cynodont recorded in the Cerro de Las Cabras Formation, would have presented much smaller autopodia.