A long fossil trackway assigned to an ungulate from the Chiquimil Formation (Late Miocene, Messinian), Santa María valley, Catamarca, Argentina

Abstract

The late Neogene sediments in northwestern Argentina have yielded a rich assemblage of fossil vertebrate remains, primarily consisting of skeletal elements. While these remains have provided valuable information, incorporating other types of evidence could further deepen our understanding of past communities. In this contribution, we study fossil trackways preserved in the Chiquimil Formation (Late Miocene, Messinian) of the Santa María valley, Catamarca Province, Argentina. The footprints exhibit a tridactyl morphology with distinctive features (e.g., U-shaped concavity on the posterior margin, central digit longer than the lateral digits), which has allowed their attribution to Macrauchenichnus cf. M. troyana. This finding is one of the longest and best-preserved trackway assigned to this ichnotaxon. The morphology and estimated body mass of the trackmaker align with hypotheses suggesting macraucheniid litopterns as producers, representing the first evidence of these ungulates in the area. This finding not only expands our knowledge of the paleobiodiversity of the region but also presents a unique opportunity for educational and ecotourism initiatives. The accessible location of the trackway and its potential for promoting scientific knowledge and local development make it a valuable resource for the community.